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Katsuki knew this voyage was cursed from the moment he saw the captain’s map pinned to the table, red points dotting waters that Katsuki knew all too well. He shouldn’t have agreed to join them, but something deep in his gut spurred him onward when whispers of a vacancy on their tight-knit crew reached his ears. And who would deny a Bakugou mer expert when they’d planned to sail right for mer territory?
His own crew had bitched and moaned about being landlocked and left behind for the next few days, but all it took was one sharp look from Katsuki and they shut up. Mostly. Denki couldn’t shut his mouth if he tried.
Their journey may have started as any other, with restless energy from the excitement of the hunt, but now there was trouble in the waters. The swell was tense, the horizon hazy. The birds did not call when they flew past. Katsuki secured the rigging as they crossed into sacred waters, the red and brown coral reef marking the edge of the mer territory.
His gut twisted–he knew the voyage would swerve this way–and yet that knowledge hadn’t prepared him for the dread seeping out of his pores. He’d have less time to sabotage their hunt now, and the eagle-eyed first mate didn’t offer him many chances to sneak away and cut their nets.
All who made their living on the sea knew the rule: you don’t hunt in sacred waters. Coral-lined reefs in shining blue waters may be inviting, may promise treasure and plenty of fish, but these waters belonged to the mer, and you don’t cross them if you want your ship to stay afloat.
But Captain Shigaraki scoffed at the tale, disregarded the warnings sent his way by fisher and sailor and pirate alike back ashore. Mer parts brought a hefty fortune on the black market, and some fences tended to look the other way when it came to a seller’s source. They didn’t care if it was a free-swimming mer beyond their pod, or one from the ancient breeding grounds where grave consequences awaited any who spilled blood in their waters.
Katsuki would rather die than let Shigaraki or his crew harm a mer.
The ship had crossed the reef just as the sun sank below the hazy horizon, and the waters flashed a brilliant pink as they approached. It was eerily quiet, the ocean rushing softly and whispering their trespass to the creatures lurking in the deep.
A chill shot down Katsuki’s spine. He never wanted to be back on dry land more than at that very moment. But he had to see this through.
What sort of curses were they inviting upon themselves as they sailed these virgin waters?
As their ship’s nets dragged in their wake, Katsuki prowled the ship with a scowl. His hand twitched toward the hilt of his knife with each passing hour. Moonrise was upon them, and the stars shimmered in the velvet sky. Silver light slid off white, crested waves and their fragile eyesight obscured by dark night and darker water. The little they could see was shrouded by the thick clouds rolling at the horizon and creeping ever closer. Even the brittle lantern light swaying along the mast looked dull and faded.
When their nets filled, the ship lagged with their added weight.The aft jerked downwards, a surge of black water flooded the deck as a cresting wave shoved them aside.
Katsuki’s heartbeat thundered in his ears; there was a pair of high-pitched warbles that shattered the air. Young, effervescent voices crying out into the dark. By the shouts and jeers from the rest of the crew, Katsuki knew it wasn’t a school of mackerel flailing within their fibers.
His whole body froze, muscles locking as the unfamiliar sound of a captured mer drowned out the crew’s shouting. He barely registered what they were saying, hoping he could still save the mer before it was too late.
“Two! Oi! There’s two!”
“Wait, wait, watch it! Watch it!”
“You idiots, grab it! It’s getting out!”
“Fuck–it bit me! What the hell!”
“Someone grab that fucker before it– shit! ”
Katsuki couldn’t see what all was happening through the throng of bodies jostling and scrambling. But he did hear the decisive splash of a small body reentering the sea and a gurgled cry in the mer language. The voice was chilling in the open air.
He heard the remaining mer’s strangled yelps as the crew jostled it, trying to get a hand on it as it swayed in the hoisted net.
That was when his body surged into motion. It would be a cold day in hell if he let these greasy scumbags hurt a single scale on that creature.
“Fucking–back the fuck off!” Katsuki snapped. “You wanna fuckin’ hurt it before you can sell it?”
The words were vile poison on his tongue; the very idea was unsettling beyond compare. But he knew how to speak their language.
The crew backed away from his explosive shouts, watching him with a wary eye as he snarled, pushing them away from the net.
“Leave it the fuck alone ‘til morning…” Katsuki’s voice died, breath catching in his throat as he finally laid eyes on the creature.
Slick skin met smooth blue scales as dark as the deepest seas. Hair like curled seaweed, shiny and dark green, framed a face like a cherub. That face hid pointed, deceptively dangerous teeth. The mer lifted its lip in a daring snarl, tongue flicking over the blood dripping into its mouth. It looked a ferocious beast, fins flared wide and scales flashing bright in the moonlight. A smattering of starlike freckles decorated its cheeks and followed down the graceful curve of its neck and down a toned chest.
Katsuki had never seen a creature quite this beautiful before, and he'd traveled the world twice over.
Even as the creature bared its fangs, Katsuki saw the glimmer of something more in its dark eyes. From one moment to the next, the mer’s black eyes flashed a bright green, the only trace of color he could see in this darkened night, before it faded away. The only thing he really cared to even look at right now. It was all he could do; breathe and look at this beautiful mer entangled in the nets of a ship he guided here.
Katsuki had to get it free as quickly as possible. It shouldn’t be on their ship, just as much as their ship shouldn’t be in its sacred waters.
He clicked his tongue to bring his mind back to the matter at hand.
“You already cut it, you idiots.”
“Well, how else are we supposed to keep it from getting away?” a blonde girl—Toga-something– pouted. She twisted the dagger in her hand, slick with blood, and there was a dark glint in her eye that Katsuki hated .
“Tie it up! No wonder you needed a fucking expert on this ship,.” Katsuki growled, shoving his way between the net and the rest of them.
He turned his back on the crew to watch the mer twist and flail as one came to secure its arms behind its back. The mer managed to latch onto his forearm and dig its teeth in. The pirate squealed like a pig and stumbled away, tripping over his own feet.
Katsuki snorted and kicked the pirate’s foot aside and pressed in close enough to smell the salty tang of the mer’s skin.
“Play along, ‘kay?” Katsuki whispered, dragging his index and middle fingers over the pulse point at the mer’s arm in the traditional greeting. The creature jolted, eyes wide and jaw slack, as Katsuki yanked the fallen rope up. “Trust me.”
The mer watched him with his stupidly big, beautiful eyes, gone pliant in his grip. Katsuki shouted over his shoulder at the lurking crew, “Get off yer asses and fucking do something useful!”
One of the others muttered under their breath—a quiet, “Who put you in charge?” that Katsuki still caught—as he tied the mer’s arms behind its back. Katsuki met the poisonous glare with an even stare and crossed his arms across his chest.
“Your fucking Captain, that’s who,” Katsuki snarled. “Cause you idiots have barnacles for brains and couldn’t tell a mer from a siren even if one was telling you to jump ship.”
Someone let out a tiny chuckle, but it wasn’t any of the crew. Katsuki turned to look at the mer with a raised brow, taking in the flush to its cheeks and the faint smile it hid in its shoulder.
“Get the fuck back to work,” Katsuki said to the crew, as his eyes remained locked with the mer’s. “Nothing we can do about it now.”
The crew grumbled but shuffled away nonetheless, finally leaving Katsuki to take in the scope of the damage they’d wrought.
“You hurt?” Katsuki grumbled, taking a closer look at the mer. There was a scrape on its forehead and blood under its nails, his chin and fangs red; it gave as good as it got when it was trapped in their nets. Seeing it pressed into the swinging net, rough fibers rubbing against smooth, luminous scales, disturbed something awful in his chest. Katsuki wanted to beat every idiot on this ship for putting this beautiful creature in this position. Anger twisted with sadness deep in his gut, a roiling bubbling fountain of distress.
What if he had never gotten on this ship? How much more pain would it have been forced to endure?
One thing crystallized in his mind: when he was done with them, Shigaraki’s crew would never sail these seas again.
“I’m not going to hurt you,” Katsuki said, offering up his wrist to return the mer greeting.
Great green eyes watched Katsuki carefully, unblinkingly, as he took in the mer’s taut form. The glittering in its eyes faded when it focused on Katsuki, wary of him. Which… fair.
“What’s your name?” Katsuki said instead, grabbing the swaying net and holding it steady. “M’name’s Katsuki.”
The mer cocked its head like a fucking puppy trying to understand.
It looked at Katsuki with wide, bright eyes, gaze unblinking and hesitant. It opened its mouth and its tongue flicked out to lap at the red staining its skin. Was it posturing at him, trying to remind him he had the means to tear him apart?
A thrill ran down his spine and Katsuki forced himself not to think about those teeth at sensitive flesh, those lips–probably wet and warm and a touch salty–and instead focus on the mer. It’s stained lips pursed into a thin line before pushing into a pout. It grumbled deep in its throat, almost sounding frustrated.
Was it trying to speak? Katsuki wasn’t fluent in the mer language, though he knew enough to know how vastly different it was from his, how it was hummed and vocalized in a way to be heard through the water. The mer was struggling to form his name.
A flash of possessiveness gripped his chest; something about the mer wanting to say his name made him excited.
He repeated his name, stressing each syllable slowly and clearly, emphasizing how to shape his mouth around each character.
“Ka…” The mer chewed over the sound, the human language strangled in its throat. Mer vocal chords weren’t suited to this language or to speaking without water. The few times he’d spoken with mer, they always sounded choked up, like they were trying to talk while holding their breath. But the sound of this mer trying out his name made him feel breathless.
“Kacchan.”
Katsuki rolled his eyes, looking away to hide the blush in his cheeks. The almost childlike nickname flared through his chest. Sure, the mer was covered in blood, but it could have been innocent without that context. His mind flashed to what it would sound like breathed softly into his skin.
Katsuki nearly smacked himself to get his mind to stop twisting around to stupid things like that.
“Yeah, sure. And you?” Katsuki huffed, glancing back at the mer through narrowed eyes.
The mer gurgled something in its own language, a tiny smile lifting the corners of his lips before he schooled his features back to neutrality. Katsuki didn’t catch anything resembling a name.
“Hah?” He went for an incredulous half-shout so he wouldn’t seem so stupid.
The mer gurgled again. “–ku.”
“Deku?” Katsuki twisted the net so the mer wasn’t compressed by the fibers so much. He picked at fraying threads, noting which would be the easiest to cut later.
The mer shook its head, drying curls fluttering and catching in the net. “–zuku! Eeee-zuuuu-kuuu.”
“I’ll call you Deku. S’only fair after the stupid way you said my name,” Katsuki said.
Deku huffed, blowing a wayward curl from his face. And Katsuki knew now that it was a he, now that he had a good chance to take in his coloring and the subtle shape of his scales. He wanted to run his fingers down Deku’s tail, feeling the smooth ridges and trace the outline of his frilly fins.
“Not fair,” Deku grumbled.
“You’re really gonna complain about a nickname when you’re stuck like this?” Katsuki plucked the net like a lute string.
The easy slope of Deku’s shoulders disappeared; he hunched into himself, arms wriggling as he struggled against his binds. Katsuki cast a quick glance around the deck. Too many of the crew still lingered, shooting furtive glances towards them.
“I wouldn’t trust anyone aboard, if I were you.” Katsuki said quietly. “They’re going to kill you.”
Deku glared at him, his button nose scrunching up in a cute way that made Katsuki want to bite him. He probably tasted like salt and sun.
“And you?” Deku said, his voice a gentle current, each word light as air.
Katsuki hmphed. “Trust me, or don’t. I’m just as much a part of this crew as they are.” He leaned in, pressing flush against Deku’s wet side, and shifted his bandana to reveal the pale scar that ran up the side of his face. Deku sucked in a breath.
“But I was at the battle of the UA reef three summers past,” Katsuki whispered, pulling down the collar of his shirt to show the starburst shaped scar just above his heart. “I protected the sacred waters from the pillagers aboard the All For One. I took these for your seas, and I would do it again.”
Deku shifted, sitting up straight as best he can and leaning into Katsuki’s space with wide, watery eyes. He looked Katsuki right in the eyes, sparkling jade meeting stormy red. Their faces were half shadowed in the silver moonlight.
“I remember you,” Deku whispered. “I remember . You saved–”
“Chatty one, isn’t he?”
Katsuki jumped, standing ramrod straight and pulling away from Deku’s orbit. He’d been pulled in like a ship caught in a whirlpool, ready to sink into his depths. It was the first mate—a shifty fucker with piercings all over his face and burn scars marring his pale skin in a patchwork of purple and black.
“Dabi,” Katsuki grunted.
“Should we cut his tongue out? We could use the peace and quiet.” Dabi prowled closer to the swinging net. Deku didn’t flinch, didn’t shift away. He just lifted his lips in a quiet snarl, sharp teeth on display.
“And sink his worth?” Katsuki said, shrugging to hide the sharp jolt of panic that shot down his back. If you bark at the crew loud enough, they’ll listen, but Dabi didn’t give a fuck who shouted the loudest. He did as he pleased, with little regard for the consequences. If he wanted to cut up Deku, he would, just for the fun of it. “Good luck explaining that to your captain.”
“Think he’ll be fine.” Dabi flashed that smarmy grin, eyes half-lidded like he hardly cared what was going on around him. “Tomura doesn’t know what he’s got aboard, not really.”
Katsuki furrowed his brow. He hadn’t seen anything out of the ordinary on their journey, and the way Dabi was looking Deku up and down had Katsuki gritting his teeth.
Slowly, Dabi dragged his finger down Deku’s cheek. Deku snapped at the appendage, baring his teeth even as his face paled.
“Really don’t want this one alerting the other mer, do we?” Dabi mused. “Shouldn’t be more than a quick cut.”
“You really think the pods haven’t already been alerted?” Katsuki said, crossing his arms over his chest to stop him reaching for his knife. “After you already let the other one escape?”
“Idiots, all of them.” Dabi snarled. “Doesn’t matter. We’ll circle round and catch our next haul tomorrow night. Have more to cut then.”
Katsuki nearly snapped back, but the wide eyed look Deku flashed him made him bite his tongue for once. Whatever mer had escaped their nets earlier was someone important to Deku. And the last thing Katsuki wanted was to put any others in danger. He already had plans to release Deku that night, make it seem like some sort of accident. Like he’d slipped out of the net on his own.
But he would have to escalate. Like his own idiot crew liked to say, plus ultra.
Katsuki clicked his tongue. “Whatever you say.”
Dabi smirked, knowing eyes flicking up and down Katsuki’s form, catching on his exposed scars.
“Y’know,” Dabi said, shoving his hands into his pockets and sauntering over into Katsuki’s space. He smelled of ash and burnt hair. “My old man was at the same battle.”
Katsuki stilled. “Was he.”
“Big ol’ fire took out his ship,” Dabi said, near wistful. “Shame he survived. I thought I got the Alchemist’s Fire right that time.”
Katsuki grunted. His own sails had caught that fire as the Endeavor sank. They were probably sailing right over its burnt husk laying at the bottom of the trench.
“Though the aftermath was beautiful,” Dabi chuckled. “Made a whole mess of the other ships.”
He mimicked the sound of an explosion. Katsuki’s ears rang.
“Think I’ll be sure to get the formula right next time.” Dabi threw an arm around Katsuki’s shoulder and brought him in close enough to whisper into his ear. “Got it nearly hot enough now.”
“Good for you.” Katsuki shoved Dabi’s arm off. “Don’t miss next time.”
Dabi scowled. A heartbeat later, he returned to his feigned nonchalance and shrugged again. He walked off, tossing over his shoulder, “Oh, I won’t, little dynamite .”
Katsuki cursed and turned back to Deku. He looked rattled, but unhurt.
“I’ll be back, okay, Deku?” Katsuki said. “I’ve got some things to take care of first.”
“Kacchan?” Deku said, shoulders bunching up to his ears.
“Promise.” Deku said something else, but Katsuki was already hurrying below deck. It wouldn’t be long before they left the reef behind, so he had to work fast. Especially if Dabi was onto him.
Katsuki would be lucky to see sunrise.
When Katsuki emerged above deck some two hours later (would have been faster if he wasn’t trying to keep as inconspicuous as possible), he was covered in ash and his hands were singed. If he’d done everything right, he had about twenty minutes to get Deku off the ship. They had changed course while he was working, shifting around to reenter the sacred waters across the reef.
He spied the crow’s nest; it looked empty from his angle. Jin was supposed to be on lookout, but he must have fallen asleep. Still, Katsuki crossed the deck on silent feet and freed his knife without so much as a whisper of steel on leather.
Deku dozed in his net, still tied, but he stirred when Katsuki gripped the net.
“Kacchan?” Deku rasped.
Katsuki shushed him as he started cutting the net away. After a few minutes, he made a hole big enough that he could reach in and sever Deku’s binds for good measure.
“What–”
“Shh!” Katsuki hissed. “I don’t got time to be shushing you, so let me work.”
Deku fell silent, watching Katsuki with those shimmering jade eyes. Something tight wound in Katsuki’s chest, but he shoved it aside and reminded himself why he was doing this.
So long as Deku could reunite with his pod, it didn’t matter if Katsuki ever saw these eyes and sparkling scales again. It didn’t matter if he never saw his crew or the sun breaking over the sea at dawn again. He was a Bakugou, and Bakugous protected the hunted.
Finally, Deku’s arms were freed. He began to struggle with the net, trying to pull it apart with hands and teeth.
“Sit still!” Katsuki said, flicking Deku on the forehead. “Don’t wanna cut ya’.”
Katsuki sliced the net open, working at it methodically until the hole was big enough for Deku to slip through. Deku warbled a warning, tugging at Katsuki’s sleeve and pointing behind him. Katsuki shrugged him off, intent on widening the hole.
A thud of boots against the deck and a scrambling of feet and a shout. Deku grew more insistent, nearly ripping Katsuki’s shirt apart.
“Stop! I can’t– fuck! ” Katsuki stuck the finger he’d just sliced in his mouth to suck at the wound, glaring at Deku. “I’m almost done for fuck’s sake!”
“They’re coming!” Deku said, looking worriedly between Katsuki and the commotion rising behind them.
Katsuki had been found out. A little quicker than he had hoped for, but he could manage. He worked to untangle Deku’s fins from the net while Deku hissed and spat in the direction of whoever was coming at them. Katsuki glanced up for just a moment to see Dabi directing Jin towards the captain’s quarters near the prow of the ship. Dabi reached for something at his hip.
He cursed under his breath. Looks like he was out of time. Throwing caution to the wind, he shoved the the support beam, the salt-encrusted wood groaning in protest as it shifted and swayed until the net hung nearly over the edge of the ship.
“Go!” Katsuki hissed at Deku, who was still doing his best to untangle himself.
A sharp crack split the air, and Katsuki felt a searing sting graze his cheek. As he spun slowly around, he could see Dabi holding a smoking gun, twirling it loosely in his hand. He grinned lazily at them, eyes glinting in the moonlight.
“Told ya not to miss next time,” Katsuki said, stepping between Dabi and the net. Deku just needed to get himself free and he could haul himself over the railing and back into the water. So long as Dabi didn’t aim the gun at the mer, it would be fine. Katsuki would take as many bullets as necessary to keep from spilling any more mer blood.
“Who says I did?” Dabi’s mouth curled into a cheshire grin, holding the gun limp in his hand like he hadn’t a care in the world. “I hit exactly where I meant to.”
Katsuki narrowed his eyes and twisted quickly to check on Deku. No blood, but he was halfway out of the net, his long, thin fins still entangled in knots with the rope.
A second crack .
This time the pain blazed white-hot through Katsuki’s back, and he couldn’t help but cry out as he stumbled with the force of the gunshot.
“Kacchan!” Deku screeched, face splattered with Katsuki’s blood.
Katsuki ripped at the net, shoving Deku through the opening.
“Go! Don’t worry about–”
A third crack. It whipped like lightning and shook the world with its thunderous echo. It sounded closer, like it were right up against his ear.
Katsuki bit his tongue, mind hazy as a copper tang coated his mouth. Pain flooded his entire body, so much that he wasn’t sure where he was hit this time. Hip? Leg? Arm? But Katsuki struggled to his feet, icy adrenaline steeling his resolve. He lurched forward, somehow summoning a well of brute strength to rip the net apart.
Cool, wet fingers gripped his skin, palming at his shoulder wound as a distressed chitter rattled in between the roaring in Katsuki’s ear. Katsuki wrapped his arms around Deku’s body, staggering towards the railing and yanking free the remains of the bindings as he heaved him over the edge.
“Go,” Katsuki whimpered. “Get away as fast as you can, underwater. Don’t stick around, it won’t be–”
One last crack .
Katsuki’s body didn’t move. He couldn’t get his limbs to cooperate, so desperate was he to get Deku off this cursed ship. Deku wriggled and thwacked his tail against the ship’s side, yanking Katsuki down by his hair. The railing that Katsuki had been leaning on exploded in a flurry of splinters. His mind was so hazy, the ringing in his ears loud enough to drown out the crack of the pistol.
“Kacchan, no!” Deku said, eyes wide and watery, yet filled with grim determination. “You’re hurt!”
“Go!” Katsuki roared, vision swimming. He felt cold all at once, his body shaking uncontrollably.
He mustered the last of his waning strength and shoved Deku over the edge. The mer scrabbled with his sharp nails at Katsuki’s skin, dragging red welts down his chest as he flailed to keep hold. Katsuki managed to shove him off, sending him falling to the waves below as a fifth crack filled the air. He felt the bullet whiz past him, tearing through his bicep.
Katsuki’s eyesight was growing fuzzy, but he still stuck around long enough to see Deku’s head pop up over the surf. Green curls were plastered to his face, his eyes wide and distraught.
“Go, idiot! You have less than two minutes! Swim down!” Katsuki shouted, gripping the railing tightly. Was he even getting the words out? Was it just his panicked thoughts swirling in his buzzing head and all he was able to vocalize was a pained cry?
Deku didn’t move, mouth open to shout something back, but after a moment he finally dove under the waves and into the depths.
Katsuki felt the heated barrel of a gun press into the back of his skull.
“I never should have let you on this ship,” Dabi said, voice venomous.
Katsuki didn’t move. Each twitch of his muscles sent pain through his entire body. How much blood had he lost? He’d been hit twice… three times? It probably wasn’t good. Hopefully he had enough time to do what he needed, even in his current state.
“Probably… not,” Katsuki said. He fought to keep his voice level, not wanting to let his pain leak into his words.
“You really thought you could get away with this?” Dabi asked.
“Nah,” Katsuki said with the barest lift of his woundless shoulder. “I figured you all would catch on eventually. Didn’t count on you being the only smart one around here.”
“The others don’t need to be smart to follow orders,” Dabi said. “All that matters is they get the job done.”
Katsuki grunted, turning slowly to face his executioner. He slowly raked his eyes down Dabi’s form, taking in the loosely held gun, the almost lazy posture. Dabi was the perfect picture of unhurried and worry-free. He didn’t have a single tense muscle in his body.
When Katsuki barked out a laugh, Dabi scowled right back.
“Too bad about yours, then.” Katsuki smirked, leaning heavily against the railing. It creaked at his back. He dug his fingers into the wood.
Dabi glared at him, eyebrow rising in a silent question.
Katsuki huffed a breath. The edges of his vision were already going black. He flicked his eyes to the sky, taking in the moon and stars. They twinkled and shone like Deku’s scales, bright and effervescent. The moonlight felt like a bracing caress on his face, gentle and lingering.
He should have been scared; he knew death was coming for him. All those lines about his life flashing before his eyes as he stood there waiting for his end, his blood darkening the planks around his feet, were complete bullshit.
He didn’t see his childhood home on the sea, didn’t see the long devoted years to studying the creatures of the deep, or meeting his squad of idiots or the freedom of sailing aboard the Dynamight for the first time.
All he saw was bared and bloody fangs, curly seaweed hair, and flashing green eyes of the most beautiful creature he’d ever met. Of gentle breaths and the feel of his moist skin under his fingertips. He saw a life he would never get to have. A home on the coast, far from port but close to the sacred waters. Building a life merged of land and sea.
It would never be a reality, but Katsuki still kept that image close to his heart.
Enough time should have passed by now. He should have been off the ship, stolen away on the dinghy while counting down the seconds. But he couldn’t risk Dabi coming after them, couldn’t risk giving Shigaraki and his crew a chance to recover. So Katsuki waited past what was probably a reasonable amount of time and smirked.
He mimicked Dabi from their earlier conversation, his hands flaring into a little explosion. And while Dabi’s face scrunched in confusion before sudden, wild understanding, Katsuki pitched himself off the railing, falling head first towards the surf.
Dabi pulled the trigger, but all five shots were already spent.The warning shout was the last thing Katsuki heard before everything was drowned out by a massive explosion. As he hit the water, the deafening sounds of the ship burning to pieces were reduced to white noise as the current took him. Blood swirled into the sea, tinging it red with each weakening beat of his heart.
Splash after splash echoed, bodies jumping overboard, chunks of the ship sinking into the depths and pulling corpses down with them. Horrified cries mingled with the rising black smoke. A final flare for aid that would go unheard.
The crew had, after all, broken the one tennant of the seas.
Katsuki kept his eyes closed against the salt water, but he could still see the bright flames. Alchemical fire didn’t fizzle with water; in fact, if it was combined with the right kind of blast powder, it would burn hotter and longer.
Coincidentally, that’s the exact kind of blast powder Katsuki used in his gun.
Katsuki smiled to himself, and his last lungful of air left him in a stream of bubbles as he sank down to the ocean depths. Shigaraki’s ship was ashes and cinder. Whether or not the crew survived the wreckage was up to the sea now. But hopefully, their mer hunts were at an end.
His last thought, before he succumbed to the sea god’s mercy, was that at least Deku had gotten away.
Katsuki was already gone when blue-green glimmering scales wrapped around his middle, but he thought he felt a dream-like press of warm lips to his own.
Slowly, Katsuki awoke, lying atop the ground in a dimly lit cave. Dripping water echoing around him, undercut by the soft splash of surf sliding against the rocks every so often. He sat up in a panic when reality started to return to him, but sudden, throbbing pain overtook his body. It flared through his chest, his hip, searing like a brand. He curled in on himself to keep from falling apart.
Where was he? What happened after Shigaraki’s ship went up in flames? Why were his wounds sticky and cold? Why wasn’t he dead?
Katsuki sat up with a hitched gasp, trying to breathe as evenly as he could through the pain. He prodded at his shoulder where the bullet had passed through. His fingers came away sticky, but the wrong consistency for blood. As Katsuki tasted his fingertip, he made a face; it was foul, almost mudlike and pulpy. Some kind of poultice?
Definitely not blood, or pus. He tried to reach around to his other wounds, finding the same there too. Who had patched him up?
The last thing he remembered was the explosions ringing, and falling off the ship into the water. He’d been able to delay the blasts long enough to get Deku off the ship. But now, he had no idea where he was or how long he’d been out. Or how he managed to survive.
Katsuki took in his surroundings, but there wasn’t much else to the cave. Stalactites hung from the ceiling, and somehow, moss had been gathered into a makeshift bed underneath him. There was a dimly lit campfire across the rock, mostly just smoke and embers by now. He’d been here a while, then. The entrance to the cave was a small cove, a half-moon shaped beach maybe fifteen feet across. The whole thing was hidden behind a rocky outcropping overgrown with moss and patches of greenery.
He caught glimpses of the sky through the small opening, filled with sunset fire orange and dusty reds. He didn’t recognize this place, and he couldn’t see the stars to figure out even a rough location. But the deep, crystal blue of the waters sent alarm bells ringing in the back of his mind.
Katsuki was attempting to struggle to his feet when the water rushed and splashed loudly from the entrance.
“Kacchan!”
Katsuki fell flat on his ass as he looked up wildly. Deku was rising from the water, beaching himself at his side with a giant smile on his face.
“Deku?!” Katsuki spluttered. What the hell was he doing here? “I told you to get away! You idiot!”
“Kacchan,” Deku said, hands going for Katsuki’s abdomen. Katsuki flinched back–not out of fear or pain, but because he couldn’t remember the last time someone had touched his bare skin.
Why the hell was his shirt missing?
Deku looked up at him, green eyes filled with concern. “Does it hurt?”
His voice was a little strained, like speaking the human language was uncomfortable for him.
“It’s a fucking bullet wound,” Katsuki grit out, not looking Deku directly in the eye and hoping the cave was dim enough to hide the blush rising on his face. “But s’fine. I’ve had worse.”
Deku reached out, hand trembling above him. Hesitantly, Katsuki nodded. Deku’s cool fingers trailed to the starburst scars on his chest, tracing the outline gently. He could probably feel Katsuki’s erratic heartbeat pounding just under his hardened, sunkissed skin. The bullet had pierced just above the old wound.
“I know.” Deku said softly, a warbling whine coming out of his throat. “You got these for me. I remember your ship burning. I remember you.”
“You were there?” Katsuki blinked in surprise. If he’d seen Deku before, he was sure he’d remember him.
“You saved me, and my pod.” Deku nodded, eyes not leaving the scar. “They’d taken my mama the year before and nearly got Eri too. They would have if it wasn’t for you. Twice now, you’ve saved us both.”
Katsuki didn’t want to breathe too hard, lest he scare the mer away and put an end to whatever was happening here. A deep warmth was spreading from where Deku was touching him, fingers gentle as he scraped away the concoction coating Katsuki’s open wounds. The scales on the back of his hand bloomed with color and light, flashing in time to his movements. Each soft carress made the warmth build, soothing Katsuki’s pain.
He felt near drunk off it, wanting to feel Deku’s touch all over him and not just on his wounds.
“Was Eri…” Katsuki whispered.
Deku scowled. “She was caught with me on your ship.”
“Not my ship,” Katsuki said quickly, bitterly. “Went with them to make sure they couldn’t hurt you.”
Deku looked up at his face, eyes wide and cheeks flushed. “Me?”
“W-Whatever mer they caught,” Katsuki stumbled, breaking their eye contact, “I mean. Wasn’t you specifically.”
“Oh.” Deku’s face fell and his brow furrowed. His plump pink lips dragged into a frown.
Why did Deku sound disappointed?
Katsuki cleared his throat, trying to chase the thoughts away. “She got away, right?” he asked. “She’s okay?”
Deku nodded, his steady hand now smearing a fresh layer of poultice on Katsuki’s wounds. The methodical way his fingers rubbed circles into Katsuki’s chest was hypnotic.
“She’s okay. We’re both okay, now.” Deku hummed as he started to wrap strips of seaweed like gauze around Katsuki’s chest. “Thank you.”
Katsuki shook his head. “Didn’t do it for thanks. Did it ‘cause it’s right.”
Deku’s hands trailed down Katsuki’s chest almost absentmindedly, before they clenched into fists at his hips. Something throbbed deep inside Katsuki, something he hadn’t felt… probably ever before.
“You got hurt because of me. He shot you so many times!” Fat tears welled in his eyes. “And I couldn’t do anything!”
Katsuki shook his head, hand moving to cup Deku’s face before he could think twice about it or stop himself. “I don’t regret it. I’d do it over if it means those poachers can’t hurt you or any other mer ever again.”
“I was so scared you wouldn’t wake up,” Deku cried. He began to clean the wound at Katsuki’s hip, hands only barely restrained from shaking. “You took so long to heal and I–I…”
Katsuki steadied Deku’s hands, holding them tightly. “You saved me.”
It wasn’t a question. He knew it was true, deep in his bones, before Deku could even finish nodding.
“The explosion was so loud…” Deku mumbled. “You were sinking and I just… my body moved on its own. There were so many pieces of the ship being pulled down and you weren’t breathing, and I…”
Katsuki brushed aside the leaking tears in Deku’s eyes, rubbing his thumb across the smattering of scales on his cheekbones. He curled his fingers into his sopping wet hair and pressed their foreheads together.
They shared air for a moment; Katsuki’s heart was about to beat out of his chest. A tingle of something entirely new started low in his gut as he took deep inhales of Deku’s briny scent. He should be pushing him away, should be enforcing his personal boundaries. That’s how he was with his crew, and he’d even call them his friends on occasion, but he never let them touch him like this.
But Deku set his skin on fire in a way no one ever had before. He wanted this closeness. He wanted to be even closer .
Deku hiccuped as he cried quietly, his arms wrapping around Katsuki’s middle in a familiar way, holding him as tight as possible. Night fell outside and the fire was completely out, ignored as it was. The only light now came from Deku’s bioluminescent scales, glittering like dewdrops poised on tall grass.
It was the longest Katsuki had ever been hugged–ever been touched . His chest felt tight and his breathing hitched on more than one occasion, but he didn’t push Deku away. Just let their bodies remain pressed together, curled around each other like hands cupping a precious thing.
And maybe that’s what Deku had become to him somehow. Maybe he’d become that to Deku too.
Precious.
It took Katsuki nearly two weeks to heal enough that he could stand and walk and even start to swim. His wounds still stung and needed tending to, but they had begun to heal neatly. Deku hadn’t left Katsuki’s side the whole time, coming and going nearly constantly with food and supplies. He even brought Eri one afternoon to meet him. She was a little firecracker, with long white hair and bright red eyes. She was scarred, too, her little body holding the history of a trauma no child should ever have to know. But they took to each other well, and soon it felt like he was part of Deku’s little pod, just the three of them.
He was used to quiet nights in the cave, though. Eri and Deku always swam back underwater once they said their good nights so Katsuki could get to sleep. He should have noticed something was weird when he caught the tail end of a hushed conversation. Katsuki looked up when he heard a single splash to find Deku wringing his hands where he sat, his tail flicking nervously at the gentle surf.
“Ya forget something?” Katsuki said, stoking the fire to last through the night. They may be in the tropics, but nights in their cove grew chill with the winter wind.
Deku squeaked, jumping up and beaching himself in the process. Katsuki groaned as he got to his feet, the wounds stinging as he stretched.
“You’re gonna get sand everywhere, nerd.” Katsuki said. His usual bite was entirely gone, replaced with a fond exasperation.
“It’s a beach, Kacchan,” Deku rolled his eyes, though there was still tension held in the little (adorable) pout of his mouth. “There’s already sand everywhere.”
“Tch,” Katsuki clicked his tongue and knelt to help push Deku back towards the water.
Except Deku wrapped his arms around Katsuki’s neck and didn’t let go. The waves lapped against Katsuki’s legs. Deku breathed deeply into his neck. Katsuki’s heart stuttered in his chest and he had to manually remind himself to fill his lungs.
“D…Deku?” Katsuki’s voice was tight and quieter than he’d ever heard it.
“Um!” Deku gasped. Katsuki expected him to pull back in embarrassment, to push Katsuki away and put some space between them. To stutter and stumble over his words, wave his arms around as he tried to explain away the moment.
He just held on tighter, burying his face into Katsuki’s good shoulder.
“A-Are you okay?” Fuck . Why was he the one stuttering? Just because the mer who saved his life, who dragged him from death’s door, who was so beautiful Katsuki couldn’t breathe around him, was holding onto him like he didn’t want to let go, ever.
“Yup,” Deku chirped, voice high pitched. Katsuki could feel him tremble in his arms. “I just thought… um.”
“Spit it out, fishface.” Katsuki rolled his eyes. His wounded shoulder was starting to hurt. But he didn’t let go of Deku either.
“Rude,” Deku laughed, smacking Katsuki with the end of his tail. But that seemed to have broken Deku out of whatever weird energy had made him so restless. He melted into Katsuki’s arms, his grip loosened until just his hands were threaded at Katsuki’s nape. He pulled back to look up at Katsuki from under his long, dark lashes and smiled. A thumb brushed at his hairline absentmindedly.
“But I was thinking, if Kacchan wanted, I could stay with him?”
“Can you even go that long out of the water?” Katsuki asked as he settled into a more comfortable position in the sand.
Deku nodded. “I think so.”
“Why do you even want to?”
Deku flushed bright pink, his bioluminescent scales lighting up brightly. He buried his face back in Katsuki’s neck. Katsuki felt Deku’s next words brushed against his skin instead of hearing them.
“I miss Kacchan at night.”
Katsuki burned .
“Hah!?” Katsuki cleared his throat and pulled Deku out of his hiding space. “Quit mumbling like that, I can’t hear you.”
Deku’s big eyes were wet with glistening tears, his lower lip sucked under his teeth. He chewed on them. Katsuki hoped that Deku couldn’t tell that he’d heard him loud and clear. But he wanted to look Deku in the eyes as he said it again, wanted to to hear it over and over.
Deku swallowed, fluttering his beautiful dark lashes. The way he looked up at Katsuki made him want to ruin him. Katsuki settled for gripping Deku’s hip, rubbing along the edge where his scales turned to human skin. Deku was warm to the touch, flushed all the way down his chest. Katsuki held his hip bone and didn’t even realize he was ducking his face towards Deku until their foreheads touched and noses brushed.
“What did you say, Deku?” Katsuki whispered.
“I…I miss Kacchan at night.” Deku said, not breaking eye contact this time. “When we have to leave him. I want to stay. So tonight I…”
“You decided to stay?” Katsuki said. He had to pull back, just a little, because the closeness was making his head swim.
Sure, he and Deku were close. He was enamored by the beautiful creature, and Deku was besotted with his Kacchan. That much was clear, even to Eri who scoffed and rolled her eyes whenever she caught the two of them lingering with each other. He’d overheard her mutter, “just kiss already,” more than once.
It was all Katsuki could think about after that.
Katsuki let his gaze linger on Deku often. Their knuckles brushing when they floated in the surf send fire through Katsuki’s limbs. They hadn’t hugged again–not like they had that night Katsuki woke up–but they always remained close to each other, always within arm’s reach.
Katsuki had been having dreams recently about leaving, and he always woke with a terrible pain in his chest. He didn’t want to leave Deku. Didn’t want Deku to leave either. In just the time he’d known him, Katsuki came to realize he couldn’t imagine a world without Deku at his side. Each physical wound that healed with Deku’s magical touch tore open a new one in his heart.
Deku moved his hand to Katsuki’s cheek and swiped his thumb under Katsuki’s eye. When did he start crying?
Katsuki sniffed, trying to will the tears away. It didn’t work.
Deku cupped his face with both hands. “I always want to be with Kacchan.”
“Fuck,” Katsuki grumbled, nuzzling into Deku’s hold. His chest felt ready to burst. He wanted Deku so bad, but he knew it would just make his inevitable departure hurt all the more. He had to make it back to land, his crew needed him. He needed to be sure no other pirates would come hunting mer. He needed to be sure Deku and Eri would stay safe.
But he knew a life away from Deku would be miserable, and he couldn’t keep living in this tiny cave.
“Does Kacchan… want me here?” Deku squirmed in Katsuki’s hold, but didn’t break free or move away.
“Fucking of course I do.” Katsuki said, pulling Deku into him. “I want you here. I want you at my side always. I want… I need you here. Because I miss you too.”
Deku wrapped his arms around Katsuki’s neck again and squeezed. Katsuki huffed out a strangled breath and pulled Deku in tighter. Every inch of Katsuki went up in flames and he relished in the heat of having Deku in his arms like this.
“Kacchan, can I kiss you?” Deku asked into his chest, feeling the words pressed into his skin.
“Hah? Can’t hear you nerd.” Katsuki said, having heard him perfectly fine. Deku pulled back with a wry smile. Clearly, he knew Katsuki’s game.
But it played it anyway.
He brushed Katsuki’s cheek gingerly, his deep green eyes reflecting the firelight as he traced all around Katsuki’s face, lingering on his lips.
“Kacchan,” Deku said, voice breathy and low, “can I kiss you?”
Katsuki wasn’t even finished nodding when Deku surged up to press into an insistent kiss. Deku’s lips were chapped from where he’d been gnawing on them in his nervousness, and both their faces were wet with tears. But Katsuki gripped Deku tightly and hoisted him onto his lap as the mer dragged his claws into Katsuki’s overgrown spikes, tugging gently to twist him how he wanted Katsuki.
Katsuki groaned, dipping low to swallow Deku’s breathy little gasps, licking into his mouth and tonguing along those sharp teeth. Their kiss was wet and messy, maybe a little inexperienced on either side, but it was also perfect. It felt like something within him finally clicked into place. Like he’d been living day in and day out with the whole world tilted off its axis and just now, Deku popped it back into place.
“Kacchan,” Deku keened, his name sounding like a prayer on his lips as he pulled away. “Kacchan, I…”
“De–Izuku…” Katsuki was breathing heavily. Deku shivered at the sound of his name. Katsuki wanted to keep kissing Deku now that that was an option, but he also needed air to breathe. Which was stupid. Deku was all he needed. “Stay with me tonight?”
Deku smiled bashfully. It didn’t line up with the way he was moaning and gasping earlier.
“Okay, Kacchan.” Deku scratched Katsuki’s scalp. “Stay with me forever?”
Katsuki’s heart crumbled. He buried his face in Deku’s hair. It was his turn to hide. “I want to. I want to so much, Izuku.”
“But you can’t,” Deku said, voice wobbly and sad.
“I can’t stay in this cove forever,” Katsuki bit his lip to hold back the cry building in his throat. “I have to get back to my crew, I need to–”
“You don’t have to explain it to me, Kacchan.” Deku pet at Katsuki’s hair, dragging his claws in gentle paths from his scalp to his shoulders. “I know.”
“Why do you make me want to stay so badly?” Katsuki growled, latching onto Deku’s neck with his teeth. Deku yelped and it melted into a moan as Katsuki gnawed at the salty skin, bringing a red bruise to the surface. “Why do you make me want to leave everything behind just so I can be with you?”
“I-I’m sorry–” Deku bit off with a sharp cry when Katsuki dug his fingers into his hips.
“Stupid fish, making me fall in love with you.” Katsuki grumbled, kissing over the bruise he’d made on Deku’s skin.
Deku froze in his arms, gone so still it was terrifying. He pulled back and searched Deku’s face. It crumpled with tears, but there wasn’t an ounce of sadness or hurt. Just pure relief. A sparkling joy that buoyed Katsuki to the surface and kept him afloat.
“Kacchan loves me?” Deku whispered it like he could hardly believe it.
Katsuki felt his ears burn. “Yeah. I love you, dork.”
“Kacchan!” Deku laughed, his tears spilling down his apple cheeks. “I love Kacchan too!”
“Better hope you fucking do.” Katsuki smirked. “I took five bullets for you.”
Deku pouted. “Don’t remind me! Just cuddle me!”
“Hah?!” Katsuki felt the blush burn even brighter. “Can’t hear you.”
“Kacchan!” Deku whined, wriggling deeper into Katsuki’s arms. As if he could even accomplish that. Any deeper, and they’d have to fuse ribcages, share a heart and become one being. One creature, one Katsuki-and-Izuku, together for as long as they both live.
It didn’t sound like a bad plan to Katsuki.
“C’mere, dork,” Katsuki repositioned them so they were a little closer to the fire but still close enough to the water that it lapped against Katsuki’s ankles and Deku’s tail fins.
Deku wrapped around him, holding him close by the waist, and laid his head on Katsuki’s chest. Katsuki had never slept like this with someone; any time he’d ever shared a bed with someone, it was because they were crammed into one space like sardines, not out of any particular desire.
He could get used to this, having Deku in his arms, feeling his cool breath tickle the hairs on his chest, the gentle pulsing of his scales lighting up the cave like dancing fireflies. He liked feeling Deku’s chest rise and fall under his palm, being able to just turn his head to press a kiss into his hair whenever he wanted to.
The nights were no longer cold and lonely in the cove. The nights were filled with Deku’s soft snoring, the little snuffling sounds he made in his sleep. Instead of a cold winter wind taking out his fire by morning, he felt nothing but warm, slick skin pressed against his all night long.
It was the best night of sleep Katsuki had ever gotten.
After that, Izuku developed a habit of cuddling up to him at night, sliding into his embrace as the fire died. They learned each other’s bodies beside the embers, touched and kissed and made love in a way Katsuki had never experienced.
The small cove turned from a tiny hole and into a cozy hideaway. It felt more like home than any four walls Katsuki had ever been in his life. With Deku in his arms, their skin pressed to each other night after night, and days spent in the water and on the beach, it was more than he ever expected he could love. For the first time in his life, Katsuki wanted to plant his roots in one place.
But roots don’t take well in sandy beaches and deep ocean water.
They were running out of time. Katsuki was fully healed now, and he still had his crew back on land. There was no telling what trouble they’d get into without Katsuki there. He didn’t want to leave this little cove, didn’t want to leave his pod behind. He put it off as long as he could, but eventually, he had to stop stalling.
His heart was heavy as he dragged planks of driftwood and felled scraggly trees on the beach. He couldn’t look Deku in the eye; if he did, he’d break down. But they both knew this was inevitable, didn’t they? Katsuki felt like his chest was breaking in two every time he caught Deku staring listlessly at the shore.
Once, he caught Deku’s face and Katsuki’s knees buckled under him. He looked so lost, so sad, that he very nearly said fuck it and destroyed his raft. Katsuki would do anything to keep that awful look off Deku’s face, but they both knew he had no choice. He couldn’t go on living in the cove like he was, and he had things to settle ashore.
So he beat down the gut wrenching feeling that gnashed at his insides every time he spied green hair bobbing away. He didn’t let the longing lashing at his chest break free in the daylight. It was only at night, when he and Deku clung to each other more desperately than before, that he let the tears out. He let them drag silently down his face without wiping them away, let them drip into Deku’s hair. Katsuki always woke with a wet spot on his chest where Deku pressed his face in the night.
He spent several sleepless nights wondering if he even had to go. Katsuki could make do living in this tiny cove of a home. He didn’t need much, just Deku and Eri. He would happily make his entire day-to-day revolve around the two mer, if it would make them happy for the rest of their lives.
Each time Deku sniffled a broken “ Kacchan ”, in his sleep, the desire to stay grew deeper. Each time he caught Deku’s eye and the riotous guilt plunged a dagger into his chest just left him feeling like he was making a mistake. When he saw Deku curled up at the mouth of the cove in the middle of the night, resting his head in his arms and gazing at the moon with the most distraught look on his face, he crawled along the sand like the worm he was to wrap Deku in his hold and cry silently together.
Ultimately, it was the reminder of his people waiting for him back at port that kept him from just throwing himself into the sea to be with Deku. It was Eijiro’s sharp smile and booming laugh and Mina’s sharp wit and keen reflexes that kept popping into his head; how they looked in the nights they shared a watch, hands entangled and heads tilted toward each other to ignore what was going on around them.
It was Hanta’s collected calm that could see them through any rough patch, the stupid jokes he repeated over and over, Denki’s manic energy that flared higher with each new trip, his ineffable way of making friends in any new port and then drinking them under the table.
They were just as much his pod as Deku and Eri were. He may not be able to tell them that to their face, but he’d been gone far too long for a routine fishing hunt, and he had no idea if news of the ship’s demise had even reached shore yet. He didn’t want to remain an endless wait for his friends. He needed to let them know he was still alive.
It was hard, but so long as he woke with Deku in his arms, he could remind himself that he would have this again some day.
Nothing was harder than the day Eri cornered him alone.
“Kacchan,” Eri said, fidgeting with her pink and red patterned tail frond. She didn’t focus on anything until she steeled herself, took a deep breath, and locked her cherry red eyes on his. “Don’t go.”
Her eyes were wide and wet and begging him to listen. It hurt worse than taking five bullets, worse than getting stabbed for defending the mer territory and watching his ship burn for it, worse than drowning. His heart felt irreperably shattered.
“I’m sorry, squirt.” Katsuki said, petting through Eri’s long hair. She was so small against his hand. “I have to. But I swear it won’t be for long.”
“But why?” Eri’s lower lip wobbled before she threw her arms around his waist in a crushing hug. He lifted the petite mer from the water and held her close to his chest. “Why do you have to go?”
“There’s a few things I need to take care of on land,” Katsuki explained. “I have people waiting there for me.”
“But what about us?”
Katsuki pressed a kiss to her forehead, right above a scar she’d gotten from the poachers who’d caught her a few years ago. It was a mottled mess of scales and flesh healed wrong, and it made her look like she had a horn.
“I won’t make you wait forever,” Katsuki said, “I’ll be back as soon as I can. And then I’ll stay. Okay?”
Eri sniffled into his chest, rubbing her snotty nose all along his collarbone. He let her cry in her arms as long as she needed to, rubbing her back in little soothing circles until she calmed down.
“I guess.” Eri sniffled.
“I’ll need you to take care of Deku, got it? He’s gonna need a lot of help while I’m gone.”
Eri stiffled a smile as she nodded.
“Knew I could count on you, squirt.” Katsuki kissed her head again and again until she wriggled out of his hold.
He let her go and tried to ignore the empty feeling in his arms. It was going to be like that for a long time before he could hold his pod again. He was going to miss that feeling every damn day until he got it back.
And then it was time to go.
Deku and Eri trailed after him, helping push his vessel landwards.
It was a long trip on the open ocean, veering in and out of sight of land on the horizon. They had far to go. It was a somber journey, filled with tense silences and lingering looks. Even with his constant promises that he’d return, he still caught the tinge of insecurity in Deku’s eyes.
It didn’t help that every time Katsuki tried to talk to Deku, he’d just give a fake ass smile and say it was fine. He clearly wasn’t, not with how his eyes were red and puffy all the time or how he would take any chance to get away from them to find food when really it was to cry outside of their earshot.
It was maddening, having Deku so close and yet so far away. Katsuki wanted to hold him, to talk to him, to let him know that he was choosing Deku every day, over and over again.
When they would rest for the night, Deku and Eri half lounging on the raft and half in the water, Katsuki kept his eyes on the sky. He traced the consetellations above, soaked in the silver moonlight, and only let himself cry when he was sure Deku was asleep.
Not that Deku got much sleep on this journey. None of them did.
And a few days on the open ocean later, Katsuki caught sight of the port. Deku caught sight of it too, physically recoiling when it appeared over the distant horizon. They’d reach it by dusk that night.
Their goodbye was bittersweet, with lingering touches and frantic, hungry kisses. Deku didn’t want to risk Eri getting too close to port in fear of being caught again.
“I’ll come back. I swear,” Katsuki murmured into Deku’s verdant hair. He trailed his hand down Deku’s side, tracing the scales at his hip before sweeping across his stomach in a featherlight touch. “I promise, Izuku.”
Deku couldn’t say a word through his choked sobs. He held Katsuki tightly, his claws piercing the skin on his back. Katsuki’s didn’t mind. He’d take any kind of reminder that Deku wanted to leave with him.
He pressed as many kisses as he possibly could all over Deku’s face until the mer was laughing and crying in tandem. Deku smiled up at Katsuki through tear speckled lashes, his eyes so green and still sad.
“I’ll miss Kacchan,” Deku said, taking the hand Katsuki was still using to hold his tummy and bringing it to his lips so he could kiss each knuckle gently. “I’ll miss you so much.”
“I know, baby.” Katsuki pressed their foreheads together, sliding a hand to Deku’s nape to hold onto the curly green hairs.
They separated, eyes lingering on each other’s, drinking in their features and memorizing their faces. They’d only have memories for the next long while.
Katuski turned to Eri, who floated beside them, watching with little sniffles the whole time. Her eyes were as wet and glassy as Katsuki’s.
Hepressed a firm kiss to Eri’s forehead, right above her little horn scar. “Take care of him, squirt.”
Eri nodded, her lower lip trembling. She was all sad seriousness, forcing her wobbling lip into a pout, clinging to Katsuki and the raft. She reached out to hold Deku’s hand. She trembled in Katsuki’s arms, and he knew she was putting on a brave face. She might be a little spitfire, but she was as quick to tears as Deku was.
Katsuki didn’t blame either of them. He was just as much of a mess as they were.
He cupped their faces.
“Wait for me there,” Katsuki said, holding onto the pieces of his heart he was about to leave behind, “I’ll be there come spring.”
Katsuki paddled his raft to shore alone, but he felt their eyes on him the entire way. Each wave he crested had him hitching his breath and heaving out a ragged sob. For the first time, he didn’t feel elated to see port. Usually he couldn’t wait to put some space between him and the sea for a few days while he recovered after a journey.
Now, all he wanted was to swim back frantically and throw himself into the ocean’s embrace.
He dragged himself ashore and stood there, looking out at the horizon where Deku and Eri watched and waited. He raised an arm; one fist went up in the distance. Fear burst through his chest like a gaping bullet wound. Where was Deku? Why was Eri out there alone? Did Deku leave already, unable to watch Katsuki swim away?
Katsuki was halfway through dragging his raft back into the surf in a blind panic when he heard his name cried out.
“Kacchan! Kacchan!”
Deku was riding the cresting waves up to the shallows, dragging himself up the beach towards him.
“Idiot!” Katsuki cried, abandoning the raft and running to pull Deku into a tight hold, “You’re supposed to stay with Eri!”
“I needed to say goodbye.” Deku sniffled, clinging to Katsuki, yanking him down by his hair to kiss him, all tongue and teeth.
“Deku,” Katsuki sighed, a relieved prayer to the only god he cared about. “It’s not safe for you up here.”
“Don’t care,” Deku gasped between hungry kisses, “Wanted one more.”
Katsuki indulged him–how could he possibly say no?
He took as much as Deku would give him and gave back twice as much. Katsuki had to pull away first, because if he didn’t, they’d fuck right there in the surf. He didn’t want sand in any irritating places, but he especially couldn’t risk the wrong kind of person spotting Deku.
“You have to go,” Katsuki murmured, kissing below the shell of Deku’s ear. “Can’t leave Eri alone for so long.”
Deku whined as he pulled away, brushing back Katsuki’s mussed up spikes.
“You’re coming back.” It was a statement, not a question.
“Course I am, shitty Deku,” Katsuki huffed, biting into the apple of Deku’s freckled cheek. “By spring.”
Deku nodded, stole one last quick kiss and took Katsuki’s heart away as he swam back out to Eri. He watched him get smaller and smaller until he could barely make out his figure and then the mer were gone, swimming back to their sacred waters to wait for Katsuki’s return.
Chest empty, Katsuki dragged himself off the shore and onto the pier, tears trailing down his cheeks and a deep and aching numbness settling into the space where his heart had been. He itched to turn around with every step.
But he had people to see and things to do before he could see his pod again.
To say his crew were happy to see him again would be an understatement. They’d all shrieked when he staggered into their usual haunt, racing from the bartop to dogpile on him in the doorway. News of Shigaraki’s ship going down had reached them weeks ago. There had only been one survivor and when it wasn’t Katsuki, they’d assumed he’d died.
Dabi had been the only one to show back up after the explosion. He was still out there somewhere, and that made a twisting mixture of fear and anger bubble in his gut. His only consolation was that it didn’t seem like Dabi knew Katsuki had survived, either.
If he and Dabi ever crossed paths again, he would make sure that he was the only one to walk away.
For now, Katsuki had a scant few months to prepare for his return. It took six weeks and way too much pestering from Mina before he told his crew what he was doing. They’d been bewildered, but redoubled their efforts to help him secure everything he needed.
He wouldn’t admit it aloud, but he appreciated their help. He couldn’t go a day without thinking of vibrant green curls and sparkling jade eyes and blue-green luminous scales glistening wet in the dimness of their cove. Each time he saw something green, his empty chest rocked with an ache so deep he would cry. The first time Eijirou caught him like that, he thought something had gone seriously wrong and was already preparing to hold another funeral for him.
The only thing wrong with Katsuki was that he wasn’t with Deku.
He hadn’t made much progress in settling his affairs and getting their ship ready for the voyage. It had delayed his schedule that whenever he wasn’t going insane over missing Deku, he was panicking over not getting back to them soon enough. But once his crew knew everything, things started to move a lot more smoothly.
Eijirou had, of course, bawled his eyes out, beaming at him and calling him “so manly” for doing this. It’s not like it was a terribly difficult choice to make; Katsuki would make it again and again. The life he returned to on land didn’t hold a candle to the one he’d shared with Deku and Eri.
Spring came with warm breezes and cherry blossoms twisting through the air. They bid them goodbye as the Dynamight sailed from port under a new captain for the first time. Eijirou was the only choice to take over Katsuki’s ship. He knew he’d treat her right. He was also sappy enough to promise to visit as often as they possibly could.
Each day aboard was agony for Katsuki. He’d nearly paced a hole in the foredeck with how antsy he was being. It was smooth sailing, with bright blue skies and a favorable wind the whole time. Gulls swept down and around their ship as they traversed familiar swells. Denki had even cried when a pod of dolphins surfaced near them, chittering and spraying them with water.
But Katsuki could only think of pink reefs and their little cove that he’d craved through the winter. He craved slick scales and scarred hands in his, the salty sweetness of Deku’s lips on his. Every morning, he feared waking up and forgetting another thing about him. The shape his freckles made on his cheek and chest and shoulders, the way his bioluminescence cast blue-green shadows across both their faces when they were pressed close. The sound of his laugher when Eri and Katsuki bickered. The way he hummed when he was busy doing something with his hands, not even aware of the noise he was making.
What if by the time he got back, Deku had changed his mind? What if Deku didn’t want him anymore? What if something was wrong, what if another pirate ship had come through and caught them?
He tore through his lip, chewing through the bloody mess it had become in his worry. They were nearing familiar shores in crystal blue seas, the pink reefs marking the edge of the waters. Everything was so different coming to the sacred waters this time around. Gone was the dense fog and colorless night, gone was the fear that tasted like thunder in the air. The waters were open, the sky endless. Everything shone in a bright glimmer, the colors richer and deeper than Katsuki had ever seen before.
It was almost like the waters were inviting them in, showing them all of what could be his.
He had no eye for any of it. None of it was the right shade of green.
Katsuki kept a frantic eye on the horizon, pacing along the railing, snapping out his eye glass every twenty seconds. His jitteriness was even too much for Denki, who was like a shark and couldn’t remain still for even a second or else he died.
Eijirou was the only one who had the patience to deal with Katsuki right now, and he came up beside him to drag him into a one armed hug. It succeeded in slowing Katsuki down enough to glare at his best friend and new captain.
“It’ll be weird to sail without you, bro,” Eijirou said, even as he gave Katsuki a bright smile. “But I’m so happy for you.”
Katsuki grumbled, embarrassment flushing his cheeks. It was all Eijirou said to him since he found out about Deku and Katsuki’s plans to settle down with him. It was like he was proud of Katsuki or some bullshit.
“Will we get to meet him?” Eijirou asked.
“If he surfaces,” Katsuki grunted, his eyes watching the horizon for a flash of green or white.
For a while, he saw nothing and a flash of fear spiked through him at the thought of Izuku being gone. But finally he spotted him not far from the cove’s hidden entrance–relief easing his tense shoulders at the sight of curly green hair and shining scales he knew so well. Then his eyes snagged on the tiny, tiny curly blond head strapped to Deku’s chest. And once he put the pieces together, his heart stopped beating, his lungs ceased to function, and hot tears pricked his eyes.
It all sent Eijirou into a panic.
Not even bothering to calm his friend down, Katsuki dove off the ship and swam for his love with a frantic speed he didn’t know he was capable of, a yearning he’d hardly ever felt before. Deku met him halfway, tail wrapping around Katsuki’s legs to keep him afloat. Katsuki held Deku’s tear-drenched face, pressing a thousand kisses to his plump cheeks, clutching tightly to his curls, and breathing in his sweet and salty scent that he’d missed so much. Deku let out a sound that bordered on relief but just escalated to a chest wrenching sobbing.
Katsuki couldn’t tell if it was a happy cry or not. He pulled back to try and figure it out, but Deku just wailed and clung to Katsuki with one arm around his neck and the other clutching the swaddled babe.
“Kacchan, Kacchan!” Deku’s voice was ragged with tears. “I didn’t think you were going to come back!”
“I said I would.” Katsuki said, trying to sooth him by pulling his bangs out of his face and kissing his forehead.
“I know, I know you promised but,” Deku heaved a breath, his chest rattling, “but it was so long. You were gone so long and I thought… I thought Kacchan didn’t want me anymore, I thought Kacchan changed his mind. Kacchan deserves to have what makes him happy and maybe I didn’t make you happy. All I did was bring you trouble and pain–”
Katsuki ceased the mumbled flood of words with an insistent kiss to Deku’s lips. He bit his lip sharply and pulled back to look directly into his mossy eyes.
“Izuku,” Katsuki fought to keep his voice low and level to show just how serious he was about this, “I have gone insane over how much I missed you this winter. Every day I wanted to swim out to you, plans and people be damned, just so I could hold you again. My world was empty without you. I needed you more than I needed to breathe. Ya hear me?”
Deku sniffled, nodding along with a tiny smile.
“Fucking good,” Katsuki huffed and resumed his attack on Deku’s face. He pressed kiss after kiss onto every freckle and scale, nuzzled into his dimples and tasted his ocean slick skin on his tongue. He refused to let up.
“Kacchan!” Deku giggled under the overload of affection.
“Shh,” Katsuki hissed, kissing Deku quiet, licking into his mouth and relearning the shape of his lips. “Need to catch up.”
Deku chuckled once Katsuki remembered that he unfortunately needed oxygen. “Don’t you want to meet him?” He rested a hand atop the baby’s head.
Katsuki pulled back, gazing into Deku’s eyes for a long moment before looking down at the babe sleeping in his wrap. He was small and pudgy, looking so much like a wrinkled little dumpling that Katsuki wanted to bite him. He had curly blonde hair and a white tail, tiny fins fluttering like dainty butterfly wings in the breeze.
Katsuki swallowed, struggling to find his voice. “Will his tail–”
“It’ll darken as he gets older, it’s normal,” Deku said with a little smile, brushing a strand of hair from the baby’s forehead. The touch spurred him to wake, and he gurgled as his eyes fluttered open. Green, just like Deku’s. Deep and endlessly green. Emerald and deep ocean floor green. It was Katsuki’s favorite color.
Katsuki chest throbbed . If Deku hadn’t been holding him up underwater, he would have drowned. Everything around him stopped to exist except for those green eyes. He’d never known a happiness like this, looking down into the face of their son.
“H-his name?” Katsuki whispered, as the baby locked his eyes on his face with a startling seriousness.
“None yet. I… thought you might like to name him,” Deku said, letting his finger be captured in the baby’s tiny fist. He was crying again, but he was smiling this time. His cheeks flushed with joy as he watched their son pull his finger into his mouth, tiny little sharp mer teeth poking out from his pink gums.
Katsuki was breathless, and he couldn’t tear his eyes away from his son.
A sharp guilt twisted his stomach. He’d been gone so long. If he hadn’t been such an idiot at the start, if he’d just nutted up and asked his friends for help, he may have been here in time for his son’s birth.
And thinking of Deku doing all this alone–making a new home for them, going through the pregnancy with only Eri to support him, dealing with the birth on his own…
Katsuki ached for missing it all. For not being there for his love.
He’d make sure he would never miss another thing with Deku again. He’d never leave his side, never leave their son or Eri again.
“Name him after me!” A sharp voice shouted from behind them, breaking the stillness of the moment.
“No, me!”
“Bro! Me, duh! I’m your best friend!”
Katsuki turned, scowling up at his former crew. Denki, Hanta and Eijirou were leaning over the railing, watching them with huge smiles.
“Hell no!” Katsuki shouted at them, scowling. The baby gurgled at the noise, crying out a sharp, “Bah!” in response.
Deku cooed at the baby and kept his gaze averted from the crew.
“Who the hell is steering the ship?!” Katsuki called.
“Mina!” Denki wriggled his fingers and cooed, trying to catch the baby’s attention.
“Should name him after her,” Katsuki grumbled. “She’s the only one who can do anything right.”
There was a chorus of complaints from the ship, but Katsuki ignored them. He was too damn happy to care, feeling like he was floating on cloud nine with his love and his son in his arms. The whole world could fall apart around them and he wouldn’t notice or mind, so long as he got to keep holding them. Katsuki couldn’t stop grinning.
“Do you want to meet my idiots?” Katsuki asked, nuzzling into Deku’s neck. Deku nodded.
After dropping anchor in a move that nearly gave Katsuki an aneurysm , the crew disembarked.
They all crowded into the cove, which hadn’t seen any use since Katsuki was last there, but before long they were all gathered around a fire, laughing with Deku like they’d always been part of the same crew.
“Where’s Eri?” Katsuki asked. He thought she’d be in the cove, but she was nowhere to be found.
Deku looked like he couldn’t decide between frowning and laughing. “Oh. Well, she’s a little mad at you?”
There was a lot of cooing over the baby, but Katsuki snapped at anyone who tried to hold him that wasn’t Deku or himself. Deku placated him with little kisses on his cheek.
“Why’s she pissed?” Katsuki asked softly, not doing too great of a job of hiding his disappointment. He’d missed the squirt almost as much as Deku and had been looking forward to seeing her again. It broke his heart that she was pissed at him.
“Something about taking too long,” Deku said. There was a flash of sadness in his eyes, like he’d felt the same at some point. He gently dragged a finger through the baby’s soft hair. “She went out with some friends, but I think she’ll still come by before nightfall. We both missed you so much.”
Katsuki grunted. He could barely swallow past the lump in his throat so he just pressed his nose to Deku’s hair and breathed him in deeply. He hoped Eri came by in time to meet his former crew. They’d love the shit out of her.
And it would be the first time his whole pod would be together. He warred with his emotions for a long time until the baby in his arms brought him full into an unshakable happiness.
Katsuki held his son close to his chest, the little mer wriggling and squirming until he got comfortable in his arms. When he did, he gave Katsuki a little smile that mirrored Deku’s so completely that it brought him to tears all over again. Katsuki smiled back, heart pounding with elation. He held a whole new person he’d helped create, a creature born of mer and human, a little wriggly bean that was the best of Deku and hopefully didn’t have the worst of Katsuki.
He wanted to do right by his son, wanted to raise him to be happy and strong and free of fear of harm. Katsuki would burn the world three times over to keep his son smiling like that. He would drop everything and anything to do whatever it was his son wanted, give him and Deku and Eri whatever they needed to be happy.
“What about Haku?” Katsuki murmured to both the baby and Deku. They’d all been tossing out names left and right for the last forty minutes.
“I like it,” Deku said, leaning his head against Katsuki’s shoulder, a dreamy look in his eye.
“How about you, brat?” Katsuki rubbed the baby’s tummy, unable to stop the smile when he giggled.
“I think he likes it,” Deku said, stroking the pearly white scales of his tail. “I think Eri will like it, too.”
Katsuki nodded, still not tearing his eyes away from his son. Their little pod had expanded, and Katsuki wanted it to keep growing. He wanted to build that family with Izuku, wanted to make a life here.
“So, not to interrupt this touching family moment,” Denki said, “but I’ve been meaning to ask. Are you just going to be living in this cave?”
“Nope,” Deku said, sitting up straight with an excited gleam in his eye.
“What?” Katsuki blinked at him. He’d assumed he would find someplace dry to live while Deku and their mer family stayed under the water. He hadn’t considered the possibility of Deku having other ideas.
Deku's smile lit up the cove in a way the fire never could. He was all glimmering scales and sunshine, and Katsuki knew then he would agree to anything he asked.. “I happen to know a very talented sea witch who can cast a spell on you, so you can be with us. That is, if you wanted that… I guess she could also give me legs–”
“Yes,” Katsuki said without hesitation, “Gods, yes. Make me a part of your world.”
Katsuki rained kisses on Deku’s face, unrelenting even when Deku tried to wriggle free, hiding his flushed face behind his arms. Katsuki beamed with happiness. He didn’t care that he’d miss the way grass felt between his toes, or climbing trees, or even traveling to see his parents on occasion to their mountain home. He could find new experiences to love, new things to feel that would feel just as good or even better.
All because he had his Deku and Haku and Eri with him. He’d give up whatever body parts this sea witch needed to become mer and spend the rest of his life in the crystal blue waters with his pod.
“Man, no one is going to believe us when we tell them that this is what Katsuki turned into after one voyage with pirates.” Hanta laughed.
“Shut up,” Katsuki grumbled, but stayed pressed to Deku’s side.
“When are you going to give up your life on land and turn into a merman for me?” Mina said with a put upon pout, kicking Eijirou’s side.
“But babe! I’m captain now! I got you a whole ship!” Eijirou cried. “Isn’t that romantic, too?”
“Idiots,” Katsuki muttered, smiling at his friends and wrapping Deku tightly in his arms.
All told he wouldn’t change a damn thing. If that cursed voyage aboard Shigaraki’s ship would always have lead to this, then he would choose to go every time.
He would go through all the pain and hurt the pirates inflicted on him over and over. He would make every choice in the exact same way. It had brought him this ultimate happiness, this feeling of belonging and completion that nothing ever had before. All the sacrifices and obstacles were nothing compared to how he felt now, in this new place in his life, where he can defend his heart and home from within the waters.
He would be able to make this seas a safer place for mer and human alike, and still get to come home to the one person who meant more than the world to him. Katsuki was able to hold this mer in his arms at night and it made everything he’d gone through worth it.
If it led him to Deku, then how cursed could it have been to begin with?