Chapter Text
The sky above Kamino looked like the end of the world.
The air was thick with dust and smoke, churning in angry spirals from shattered buildings and burning cars. Sirens wailed somewhere distant. Heat shimmered above pools of flame. On one of the many ruined streets, a hulking, skeletal villain in a life-support mask stood like a black pillar in the chaos, his right arm swollen and warped with Quirks.
All For One.
He flexed that grotesque arm and felt the way power screamed through it, bones spear-like, muscles swollen by multipliers, kinetic boosters humming like engines underneath his skin. Threads of unknown minerals jutted out like blades. To him, it felt perfect.
Ultimate Quirk Combination, he thought, savoring it.
Not far away, All Might struggled to stand.
He wasn’t the towering giant who’d once grinned down at villainy and erased fear with a single punch. The muscular form clung to him like a dying flame, flickering and failing. Smoke rose from his battered suit. His right side trembled; the embers of One For All crackled weakly.
Around them, the world watched.
On a huge outdoor display in central Yokohama, the battle was being broadcast live. A crowd had gathered despite the late hour. Among them, hidden under cheap disguises, five figures stared up at the screen with devastated faces.
Izuku Midoriya, Tenya Iida, Shoto Todoroki, Momo Yaoyorozu, Eijiro Kirishima.
Just behind them, scowling at the screen with clenched fists, was Katsuki Bakugo.
“Th-that arm-" Midoriya choked, hands shaking as he clutched the rail in front of him. “He’s… he’s combining that many Quirks in one limb…!”
Momo’s eyes were wide, calculating despite her fear. “His right arm alone must have dozens of abilities layered. This is beyond anything we saw in The nomu."
Bakugo said nothing. His jaw was set, eyes locked on All Might as if he could will his mentor to rise.
On screen, All For One took a step forward. The pavement cracked beneath his transformed arm.
“All For One…” he said calmly, voice distorted through his mask, “has confirmed that the embers of One For All no longer dwell within you.”
All Might’s shoulders stiffened.
“You’re bluffing,” he growled but even his voice sounded smaller, hoarser.
“Don’t insult me,” All For One replied with cold amusement. “That body of yours is already finished, All Might. It’s time we close the curtain on this farce.”
He raised his monstrous arm.
All across Japan, people held their breath.
A few blocks away, at street level, the consequences of their previous clash lay scattered in a ring of destruction.
One building, once a modest office tower, now leaned like a broken tooth. Its upper floors sagged, half sheared away by earlier blast waves. Rubble was piled high at its base, concrete chunks, twisted rebar, shattered glass, pieces of office furniture jutting out at odd angles.
Beneath all that, something that did not belong to this world lay motionless.
It had fallen a long way.
Not through space, not even through conventional time, through something else. Through a crack between realities, a tear opened by chaotic energies far away in a different castle, in a different kingdom.
One moment, the Koopa King had been roaring at Mario atop crumbling stone, the next-
Void.
Colors stretched into threads, shapes dissolving as if dunked in acid, a feeling like being yanked by the tail through a keyhole. Rage became static. Fire died in his throat.
Then: blackness, and one last confused thought.
Peach, you better not be watching this part.
The portal spat him out into Kamino like trash into a dumpster. He hit the side of the building hard enough to make the already-unstable structure scream. Concrete avalanched. Beams snapped. Dust swallowed him whole.
The rubble settled.
For several long minutes, Bowser lay buried, unconscious, crushed beneath unfamiliar stone and metal, this alien city’s bones pressing in on his shell.
Above him, the battle raged, and he knew none of it.
On the main street, All For One prepared to end an era.
He let his mutated arm hang back, gathering power. Threads of dark energy crawled along the limb like veins of midnight. The cameras zoomed in; commentators choked on half-formed words. The screen in front of Izuku and the others showed only that terrible arm and the silhouetted, shrinking form of All Might.
“You’ve always been at your best,” All For One said, “when you throw everything away for others. So let’s see how much you have left to sacrifice.”
In one of the upper floors of a half-collapsed building, a lone civilian still lay trapped beneath fallen beams. All Might had saved her once already, interposing his body to block a blast. That was what had cost him the last of his power.
Now he stood again between her and the demon king of Quirks.
“You’re still in my way,” All For One sighed. “How stubborn.”
He took another step.
The ground answered him.
Not with a crack, not with a crumble.
With a rumble.
A low, subsonic growl rolled through the ruined street, enough to make dust dance on every surface. All For One stopped mid-step. His Infrared Quirk washed over the battlefield like a sonar ping, feeling heat signatures, vibrations-
Something was moving in the rubble of the half-collapsed building to his left.
All Might felt it too, a faint tremor under his feet. He glanced sideways, chest heaving.
An aftershock? Now?
The trapped woman screamed as the wreckage above her shifted.
From the rubble pile, a muffled noise answered, half growl, half annoyed groan.
Then everything went white.
A pillar of fire erupted from the broken foundation, exploding upward in a volcanic geyser. Flame tore through concrete like paper, shattering debris outward in a shockwave that knocked heroes and villains alike back a step. The heat was intense, burning, hungry. It tasted like something old and wild and utterly unregulated by Quirk laws.
Endeavor, still recovering from his last clash and watching the battle from a nearby rooftop, flinched, eyes reflecting the orange glare.
“What…?” His breath caught. That fire wasn’t his. But its temperature-
“That’s hotter than Endeavor’s flames!” a random officer shouted from behind a police barricade, shielding his face from the sudden blast of heat.
Midoriya's jaw dropped. “T-that thermal output…! It’s like a concentrated volcanic eruption… Is that a Nomu? Another villain?!”
The flame column roared, licking the clouds, then collapsed inward like a blooming flower folding shut.
Left behind, standing amid the cratered ruin of the building’s base, was a massive silhouette wreathed in smoke.
For a moment, most of the world thought he was just some huge, Quirked civilian who’d gotten unlucky and then triggered under stress.
But as the dust thinned, that theory got… complicated.
Bowser blinked.
His vision swam with afterimages of fire and rock. His ears rang. His back ached in that special way it only did when a castle had fallen on him.
Again.
“Urghhh… what… hit… me…”
He shook himself like a dog, sending chunks of concrete flying. His shell flexed, plates grinding against stone, spikes gouging lines in the rubble as he pushed himself upright.
Shapes slowly came into focus.
Not his throne room. Not the familiar burning banners of his castle. Not even some annoying pastel kingdom of Toads.
This was… metal and asphalt and strange-smelling air. Broken glass clung to his scales. The sky was full of smoke and noise. And everyone had gone very, very quiet.
He took a breath. The air tasted wrong, like oil and dust and faint hints of something spicy from a distant street vendor, but breathable.
He frowned, heavy brows knitting over deep-set eyes.
“…The heck… is this dump?”
To the watching crowd through television screens, he looked like a colossal, horned, bipedal “man” with a weird mutation Quirk.
He was covered in dust, his green shell smeared gray, spikes glinting beneath the grit. His red mane was matted with plaster. Broken rebar poked out of the rubble near his feet like the remains of some giant trap that had failed to hold him.
His yellow skin and thick, corded arms stood out under the bright battlefield lights. Black spiked cuffs circled his wrists. His jaw was lined with sharp teeth, lips pulled into an irritated snarl.
To All For One’s sensors, he was… odd.
Humanoid. Bipedal. Incredibly dense musculature. Strange skeletal orientation. Massive internal heat source. And yet, no Quirk factor signature in the way this world understood it.
Still, the presence was undeniable.
(Imposing,) All For One thought. (Like a living calamity.)
For the first time in a long time, someone new stood in the middle of his stage who wasn’t part of his script.
All Might stared.
“What… is that…?” he breathed.
The creature—this… man?c rolled his shoulders, cracking his neck audibly, then looked down at himself. He brushed dust from his chest with big, clawed hands and scowled at the crack in one of his shell spikes.
“Great. Another castle, another pile of rubble,” Bowser grumbled. His voice was deep and gravelly, carrying easily over the battlefield. “I swear, if this is one of Kamek’s weird magic pratfalls again, I’m gonna-"
He cut off.
He’d finally noticed All For One.
The Koopa King squinted at the skeletal villain in the breathing apparatus, the tubes, the warped arm, the dark suit, the aura of wrongness that pressed on the air like suffocating fog.
Then he noticed All Might, this big blond guy who looked like he’d been mauled by a Thwomp and left in the sun too long.
And the rows of flashing lights, the shouting humans, the distant cameras.
And the way everyone was staring at him.
Bowser’s eyes narrowed.
“…Where’s Mario?” he demanded, as if the world owed him an answer.
No one responded.
On the screen in front of Class 1-A’s little infiltration group, Bakugo’s eye twitched.
“What the hell is that thing?” he snapped. “Some kinda dragon Quirk?!”
Izuku was already muttering under his breath at hyperspeed, analyzing. “H-his body structure is unlike anything in known mutant-type Quirks. The shell, those spikes, the cranial horn structure, no, that’s not a simple heteromorph. And that fire pillar earlier… The heat output…!”
Momo swallowed. “Is… is he on our side?”
On screen, Bowser turned in a slow circle, taking in the destruction.
Then he turned back toward the nearest source of power.
All For One.
The ancient villain studied him with clinical curiosity. “Interesting,” he murmured. “You appeared from the rubble… and yet I do not recall granting such a Quirk to anyone in this area.”
He took a step forward, his massive arm flexing. “You there. Name yourself.”
Bowser bristled at the tone, shoulders flaring wide.
“Who wants to know, mask-face?” he shot back, baring his teeth. “You some kinda bargain-bin Dark Star or what?”
The fact that Bowser showed absolutely no fear in the face of the most dreaded villain in Japan hung in the air like a slap.
Even Endeavor stared. “He's seriously treating this Villain like he's nothing!?”
All For One tilted his head. How long had it been since he’d met someone brave, or stupid, enough to address him like that on first meeting?
Intrigue flickered.
“Forgive me,” he said, voice suddenly smooth and polite, the way he’d once coaxed desperate people into his palm. “I simply thought your quirk was so intriguing. Your abilities look fascinating.”
Bowser’s eyes narrowed further. He’d heard that tone a thousand times, from scheming Beans, from would-be usurpers, from sleazy salesmen trying to trick him into signing some awful contract for “interdimensional domination bundles”.
“Stop trying to butter me up,” Bowser snapped. “It won’t work. I can read you like a book, weirdo. You want something.”
All For One’s lips twitched behind the mask.
“So you’re smarter than you look,” he conceded. “I want your abilities.”
Bowser stared at him for a beat.
Then he threw his head back and laughed.
A big, booming, villainous laugh that echoed off the ruin and somehow made the destruction around them feel like part of his throne room.
“GRAHAHAHA! Sorry, chump! But you can’t handle my awesome power!”
Izuku made a strangled noise.
All Might, despite everything, felt a tiny, bewildered spark of familiarity at the bravado. It reminded him of the kind of loud, theatrical villains who used to showboat on TV.
All For One’s fingers flexed.
“We’ll see about that,” he said.
He moved first.
With a thought, he layered Quirks into his legs and spine, Springlike Limbs, Booster x4, Strength Enhancement x3, Air Walk. Air compressed beneath him. The ground cracked as he launched forward, the mutated arm cocked back for a devastating blow.
All Might’s eyes widened. “Look out!”
Police officers and nearby heroes shouted in instinctive chorus.
“Run!”
Bowser did not run.
In the instant All For One’s fist blurred toward his face, the Koopa King’s expression went from amused to annoyed.
He raised one arm and caught the punch.
The impact shook the street. Cracks spiderwebbed out from Bowser’s feet. Shockwaves kicked up dust in a circle.
Bowser’s claws dug into the grotesque flesh of the villain’s arm, stopping it dead inches from his snout.
All For One’s mind flickered with surprise.
He stopped that… with raw strength alone? No reinforcement? No barrier Quirk?
Bowser’s smirk widened, sharp teeth gleaming. “Hey, what’s the big idea, ugly!? Lunging at a guy’s face like that? Back off, creep!”
Before All For One could adjust, Bowser pulled.
He yanked the villain forward like a misbehaving minion, dragged him into his own range, and slammed a massive fist into the side of All For One’s mask.
“SHOWTIME!”
The punch sounded like a cannon.
All For One rocketed sideways, smashing through a half-standing wall and disappearing into a fresh cloud of rubble.
From the rooftop, Endeavor’s flames flickered out of sync. For a moment, he forgot his pain, forgot his envy, forgot everything.
“What… the hell…?”
On the big screen, Izuku could only stare.
“He… he just… stopped All For One’s punch with his bare hand and countered-!"
Todoroki frowned, eyes flicking between All Might and the new arrival. “That wasn’t rescue. That was… dominance.”
Kirishima’s jaw dropped. “That was so manly it’s illegal…”
Bakugo’s palms crackled with tiny explosions, his eyes reflecting Bowser’s hulking silhouette. “Tch… big lizard thinks he’s hot stuff…”
The rubble All For One had smashed into trembled, then exploded outward as he blasted free, landing with controlled force on cracked asphalt. His mask was dented, one of the tubes bent at an odd angle. His right arm throbbed from the impact.
(Such incredible strength…) he thought. (He doesn’t seem like a Pro Hero. A drop-out U.A. student who grew up? A vigilante, perhaps?)
Bowser planted his fists on his hips and struck a wide, confident pose.
“GRAHAHAHA! Is that all you got!?”
Around him, the sense of presence that had so unsettled everyone only grew. It wasn’t just physical power; it was the swagger of a king who expected the world to adjust to him.
All For One’s earlier bemusement cooled.
(No. This man is a villain to his core,) he decided.
Bowser’s aura didn’t feel like justice. It felt like conquest. Like domination. Like a blazing, selfish star that refused to be anything but the center of everything.
Which, in a way, made him… relatable.
All For One straightened his suit with his left hand, rising from the crater.
“You’re very intriguing,” he said calmly. “It’s a shame I have to take your Quirk and kill you.”
He launched himself forward again, dark energy gathering.
That word again, Bowser thought as the mask-faced freak closed in. ‘Quirk’. What the heck does that mean? Some kind of magic? Curse? Whatever.
He twisted aside as All For One’s empowered arm whipped past, then slammed a right hook into the villain’s torso. The impact sent a shockwave up Bowser’s arm and cracked the asphalt under All For One’s feet.
(He’s fast…) All For One realized, letting himself flow with the blow, riding the kinetic force into a retreating leap. (This Quirk truly is the all-in-one package.)
Of course, he was wrong.
There was no Quirk.
There was Bowser.
And somewhere deep inside the tangled web of stolen abilities that made up the copy All For One, something primal sensed that absence, and hated it.
“Let’s test your limits,” All For One said quietly.
His right arm returned to its earlier, less grotesque state for a moment, then reconfigured into a shape optimized for ranged output. Quirks layered and latched into place, spirals of dark energy coalescing in his palm.
“Spring-ify,” he intoned, voice gaining an almost theatrical rhythm, “plus Brawn Boost, plus Air Cannon, plus Rivet Stab, plus Dark Ball, plus Impure Beam!”
The air howled.
A massive vortex of compressed force and blackened energy roared forth, laced with piercing rivets of hardened matter and streaks of malignant light.
The blast tore up the street, annihilating everything in its path.
Bowser’s grin sharpened.
He inhaled.
Deep.
The furnace inside him, the molten core that had always set him apart even among Koopas, flared. Starborn power whispered under his scales, the faint echo of the Seven Star Children’s legacy thrumming awake, mingling with the darker arts he’d learned over countless campaigns.
He opened his jaws and unleashed a torrent of flame.
It wasn’t a cartoonish puff. It was a beam. A thick, blazing column of orange-gold fire that met All For One’s attack head-on.
The two forces collided mid-air with a booming shockwave.
For a heartbeat, they wrestled, a stalemate of Quirks and starpower.
Then Bowser’s fire surged.
His flames swelled, swallowing the rivets, devouring the dark light, pushing the compressed cannon back along its own path.
All For One’s eyes widened behind the mask.
He braced, forcing more power into the beam, but it was too late. The combined attack detonated between them in a swirling storm of heat and force that chewed fresh craters into the street and sent shards of concrete spraying.
For the first time in many years, All For One had to slide back a step to hold his ground.
In the distance, Endeavor’s pride screamed. “Impossible…!”
On the screen in Kamino Ward, citizens held each other, unsure whether to cheer or flee.
All For One’s annoyance ticked up half a degree.
He overturns my combinations with brute force. His biology is absurd. And still…
Why was his chest… tight?
Why did a peculiar, irrational hatred coil up from somewhere deep inside his Quirk, agitating through the neural pathways it had rewired over decades?
(Why? Am I putting this much hatred into this fight?) he thought coldly, observing himself with detached curiosity even as he adjusted his stance. (I never put this much into anything, not even fighting All Might. Even I never hated Kudo this much.)
He didn’t know that All For One, the copy of the original Quirk, was reacting on instinct.
It sensed a being of tremendous power that lay outside the system it governed, beyond its ability to steal. An anomaly. An insult.
It screamed to claim, and when it couldn’t, it screamed to destroy.
All For One, the man, merely knew that this new opponent was getting under his skin in a way that defied his carefully cultivated calm.
Bowser, oblivious to this existential crisis, cracked his knuckles.
“You done playing with fireworks, masky?” he taunted.
All For One moved.
He blurred forward with frightening speed, his mutated arm back in crushing configuration. At the last second, he feinted high, then twisted, slamming a heavy punch into Bowser’s face.
The blow landed with enough force to pulp steel.
Bowser’s head snapped sideways. Dust flew from his mane.
But he didn’t move.
He didn’t fly back. He didn’t stagger more than half a step.
Slowly, he turned back to stare at All For One.
“…That it?” Bowser asked.
Then he uppercut him.
Claws flashed. Bowser’s fist crashed into All For One’s jaw with an uppercut that lifted the villain clear off his feet, followed by a slashing rake of claws across the mutated arm, slicing Quirk-grown materials and drawing spurts of darkened, oddly-textured blood.
All For One released a blast of raw kinetic shockwave in reflex. Bowser snarled, tucking into his shell mid-air.
The Koopa King’s body spun into a green-and-yellow blur.
He became a whirling wrecking ball that hurtled through the shockwave, shredding it, then slammed into All For One like a living meteor. The impact drove the villain into the ground again, gouging a trench along the street.
All For One gritted his teeth and snapped his fingers, using another Quirk to hurl nearby rubble as projectiles. Three chunks of concrete the size of small cars broke free and launched at Bowser.
Bowser popped out of his spin just in time.
He leaped over the first chunk, shell scraping its surface with a shower of sparks. In mid-air, he tucked again, spun, and drilled through the second piece, shattering it into gravel. He landed, snapped his leg out, and kicked the third chunk straight back at All For One like a soccer ball.
It hit the villain in the face.
Hard.
Cracks spiderwebbed through the already-damaged mask.
Bowser followed, closing the distance with surprising speed for someone his size, and drove another heavy punch into All For One’s torso, knocking him flat.
From behind the police line, heroes and officers alike watched in stunned silence.
“Is he… is he helping us?” someone whispered.
All Might remained still, chest heaving. He’d been a breath away from complete collapse. Now he watched this unknown monster fight his arch-enemy in his stead.
I couldn’t finish you, he thought, teeth gritted as he forced his battered body not to move recklessly. Someone else… just walked in and-
His heart twisted. Pride warred with relief and guilt.
On the big screen, Izuku’s eyes shone with conflicting emotions as he watched Bowser slam All For One through a car.
All For One had endured a lot in his long life.
He’d been burned, blasted, disintegrated, dismembered, torn apart, blown up, and rearranged on a molecular level more than once. He’d adapted through Quirks and sheer will.
But this was new.
This wasn’t a strategic hero carefully measuring their blows. This was a brutal, overbearing force of nature hammering away at him like he was just another mid-boss.
He pushed himself to his feet again, panting quietly through the mask’s filters. His regeneration Quirks worked overtime, but the cumulative damage was slowing them.
Enough, then.
He needed to remind this upstart what a true demon lord looked like.
Bowser, standing with one foot half on his chest to hold him down, glared.
“Heh.” The Koopa King lifted his hand, dark energy coiling around his clawed fingers as he tapped into his star-born heritage. “Y’know, you’re tough. I’ll give you that. But you’re getting on my nerves.”
He drew that power inward, channeling it into his fist. Shadows flickered around his arm, mingling with the glow of internal flame. For a heartbeat, the seven-pointed radiance of primordial starpower glimmered in his eyes.
Then he punched All For One.
Hard.
The impact wasn’t just physical.
The strange, alien energy tore through the villain’s Quirk web like a spike driven into tangled wires. For someone else, it might have been just a very strong punch. For All For One, whose soul and body were laced with hundreds of stolen abilities, it was… violation.
Things unraveled.
Quirks he’d hoarded for decades shuddered and dislodged, like stones torn free from a dam. Beads of light, metaphysical representations of stolen powers, ripped free from his body in a shower of glowing fragments.
Some shot away into the night.
One, in particular, streaked like a comet across the ruined factory district, homing in on a Pro Hero who’d been left comatose and Quirkless.
Somewhere, Ragdoll’s eyes shot open as “Search” returned home.
All For One’s body convulsed.
(Impossible,) he thought, panic and fury lancing through him. (This shouldn’t be possible. I control all Quirks I have collected. I am their master. No one takes from me. Is it a result of having an inferior copy? Or something else?)
Memories flashed in his mind unbidden.
“That day.”
The blinding light of All Might’s fist. The all-consuming pain as his face had been obliterated. The humiliating crawl into the shadows afterward.
Rage, old and fresh, surged.
He roared, a sound more beast than man, and surged up with speed that bent the air. His arm crackled as he poured every ounce of spite and stolen strength into his next attack.
“I’ll turn you into turtle soup with this attack!” All For One snarled.
Bowser blinked. “Oh, now you’re talking my language.”
All For One didn’t care anymore about analysis. He’d given up on polite words.
He drew in power.
“Spring-ify, plus Brawn Boost, plus Air Cannon, plus Rivet Stab, plus Dark Ball, plus Fireball!” he howled, stacking Quirk upon Quirk until his right arm was a sun of malignant power compressed into a sphere at his palm.
Energy screeched. The air rippled around his arm, space itself looking like it might tear.
Bowser’s pupils narrowed.
This one… he needed to respect.
He dropped into a crouch and, in a practiced motion, withdrew into his shell. Plates sealed over his vulnerable front, spikes angling outward.
All For One saw.
“I’LL TAKE YOUR QUIRK OFF YOUR CORPSE!” he screamed, voice cracking with a hatred he barely understood. “NOW DIE!”
He fired.
The compressed sphere of combined Quirks screamed across the gap, tearing a smoking groove in the air itself.
For a moment, the world held its breath.
On the big screen, people flinched. Izuku clutched his chest. Bakugo hissed through his teeth.
A blast of that magnitude, at that range-
The explosion didn’t come.
Because, just as the blast was about to hit,
Bowser emerged.
He was grinning.
And he was wearing soccer gloves.
Massive, spiked gloves, each finger tipped with a wicked blade. They gleamed with some enchanted alloy, part sports gear, part torture device.
He lifted one clawed hand, still sheathed in the glove, and casually smacked All For One’s attack.
The blast reflected.
Not deflected. Reflected.
It turned back along the path it had taken, but twisted tighter, power doubled by Bowser’s dark-magic technique. The sphere shrieked as it hurtled back at its creator.
All For One had a fraction of a second to process the betrayal of his own power.
(He reflected-)
Then it hit him.
The blast swallowed him whole.
The resulting explosion turned a city block into a crater. Light flared white-hot, so bright the broadcast cameras auto-adjusted frantically. The sound arrived a split second later, a thunderclap that rattled windows kilometers away.
When the light faded, what remained of All For One’s body landed in a twitching heap.
Most of his right side was gone, scorched away to grisly fragments. His arm was a ruin. Many of the life-support systems strapped to his torso had melted or fused with flesh. His mask was shattered, revealing the horror of his scarred face, no eyes, no ears, features melted into a grotesque smooth mass.
His regeneration Quirks scrambled to rebuild him, but the damage was so total, so saturated with stolen energy, that they struggled. Healing was slow, sluggish.
Bowser strode toward him, dusting his gloves nonchalantly.
“Yeah, yeah, YEAH!” he crowed, laughter booming across the devastated street. “HAHAHA!”
He loomed over the ruined villain.
“What kind of menace are you if you can’t handle the power of your own attacks?” he mocked.
He planted one big, clawed foot on All For One’s head, pinning him like a trophy. One arm rested casually on his knee, the glow of fires painting him in hellish light.
“Harr-harr! Look at’cha!” Bowser sneered. “You look like a potato! That look suits you!”
Around them, cameras captured every moment.
Heroes stared, frozen between horror and awe.
All Might, in his fully emaciated form now, watched with wide eyes, his secret laid bare by the earlier blast yet all but forgotten in the wake of this new nightmare.
Bowser glanced around finally, really taking in the state of the city. Broken buildings, injured civilians, heroes bleeding and exhausted.
He frowned.
“…Y’know,” he said, voice dropping just enough to be heard clearly. “I can tell you’ve been causing a lot of trouble around here.”
His eyes narrowed at All For One, foot grinding down slightly.
“I find that kinda disrespectful.” He jabbed a thumb at his own chest. “Why? Because I’m the one any and all heroes should fear. Me! The glorious Koopa King: Bowser!”
Gasps rippled through bystanders. The name meant nothing to them, but the confidence did.
All For One rasped, regeneration still piecing his mouth together. Even now, he tried to goad, to manipulate.
“Please,” he wheezed. “Spare me from your speech. It hurts more to listen to you… than the fact that I can no longer punch you in the face…”
Bowser tilted his head, considering.
“…Good point,” he conceded. “I’ll just cut to crushing your head.”
He lifted his foot.
On the other side of the screen, Izuku’s heart stopped. Tenya’s hand shot out uselessly toward the broadcast as if he could stop what was coming. Momo covered her mouth. Shoto’s eyes narrowed, frost licking the edge of his breath.
Bakugo’s pupils were tiny pinpricks.
On the ground, All For One remembered with sudden, sharp clarity that this wasn’t a hero.
This was a king of monsters, and he didn’t share stages.
“Wait- don’t-" he started.
Bowser brought his foot down.
The crack was deafening.
There was no slow fade-out, no dramatic monologue, no last-second warp. All For One’s head burst under the Koopa King’s heel, leaving nothing recognizable behind. Scar tissue, bone, life-support fragments—reduced to a red, ugly stain on the broken pavement.
For a moment, there was only silence.
Then the noise hit.
Screams, shouts, the panicked babble of commentators who had just watched the most feared villain in Japan’s history executed on national television by an unknown monster.
“That’s it,” Todoroki said quietly, eyes on the screen. “He’s dead. That guy is… really dead.”
“Th-that can’t be…” Midoryia whispered, knees weak, mind running faster than Iida. (All For One… after all that history… after everything All Might told me and now...)
“He just got stomped,” Bakugo finished, voice flat and furious and disturbed all at once.
Bowser took his foot off the smear and flicked invisible dust from his leg with affected casualness.
“Harrharrharr…” He cracked his neck. “That’s that.”
He looked up at the nearest hovering news helicopter, squinting at the camera lens as if seeing it for the first time.
“Huh. Guess this world’s got some kinda magic eyeball boxes too,” he muttered.
Then he grinned, wide and sharp, and gave the camera a little finger-wave with his clawed hand.
“Hope you all were taking notes,” he said. “That’s how a real final boss does it.”
He snapped his fingers.
A familiar shape materialized beside him, summoned across dimensions by his will and latent dark magic, the bond to his favorite ride stronger than space itself.
The Koopa Clown Car.
Its round, white face bobbed in mid-air, mouth painted in a goofy smile. The propeller above whirred as it stabilized, lowering just enough for Bowser to climb in.
All Might finally found his voice.
“Wait!” he croaked, stumbling forward. Every muscle protested. His emaciated frame shook. But he had to try. “You… you can’t just… walk away! You killed- you executed-!"
“Villain,” someone whispered nearby, summing up what everyone was thinking.
Bowser turned in the clown car’s opening, one arm resting casually on the rim. He looked All Might up and down.
“You?” Bowser barked out a laugh. “You wanna fight me?”
He took in the shaking, thin frame, the sunken eyes, the blood. The former Symbol of Peace looked like a Goomba that’d lost an argument with a steamroller.
“That’s hilarious,” Bowser snorted. “Try climbing up some stairs first!”
A few of the more conscious heroes winced despite themselves.
All Might’s hands clenched into fists, shame burning through him. He wanted to shout, to challenge, to punch, but his body had nothing left.
The Clown Car rose, spinning its propeller faster.
“Later, weirdos!” Bowser called cheerily, laughter echoing through the ruined ward as he ascended. “I’m gonna go find whoever’s in charge of castles around here and give ‘em a piece of my mind!”
He turned the Clown Car toward the city lights and roared off, disappearing into the smoky sky.
In his wake, Kamino was left with silence and ash.
All For One was dead.
Not imprisoned.
Not sealed.
Not defeated in secret.
Dead.
On television. In front of millions.
The Police scrambled, shouting orders. Heroes tried to regroup. Medical teams rushed forward to treat the wounded. Some stared up at the sky, as if expecting Bowser to suddenly reappear.
At the outdoor screen, Midoriya and the others stood frozen, the enormity of what they’d just witnessed pressing down on them.
“Midoriya,” Iida said at last, voice shaky. “That… man… he… he killed someone. On live television. A villain, yes, but
Izuku swallowed hard.
(All For One was… he was…) He thought of All Might’s stories, of Nana Shimura, of the long, bitter war of ideals. (That fight, that grudge, that whole history… and he was just… stepped on.)
Todoroki folded his arms, watching the replays already looping on nearby smaller displays.
“Everyone’s going to remember this,” he murmured. “Not the long, drawn-out struggle. Not the Symbol of Peace holding the line for decades. But a monster from nowhere killing one of the most powerful villains we've seen in one night.”
Bakugo’s teeth ground audibly.
“That bastard,” he growled. “Stealing All Might’s glory like that…”
Momo’s analytical mind was already turning. “He appeared from rubble no one saw him enter. His physiology doesn’t match any recorded race. The way he reflected that attack-"
“Iida,” Midoriya said abruptly, cutting her off as his brain latched onto one terrifying thought. “If… if someone like that is walking around now… someone who doesn’t care about our laws or our system…”
Iida adjusted his glasses with a trembling hand. “Then U.A., the heroes, the world… will have to account for a new… variable.”
Above them, the screen zoomed on the red stain where All For One had been.
No one knew that, to Bowser, Quirks were meaningless words.
No one saw the portal that had spat him here.
And quirks being what they were, diverse, unpredictable, no one could even tell he wasn’t human. The Koopa King had crashed into their world like a meteor, and their system had no concept for “different species from another dimension”.
To them, he was just another terrifying villain with an absurd mutation-type body and an unknown, broken Quirk.
Somewhere out there, flying over a city he didn’t know, Bowser squinted down at the strange glowing signs and weirdly organized streets.
“Alright,” he muttered to himself. “New world, new heroes, no Mario, no Peach… but they’ve got castles, right? Palaces? Somebody important. I’ll find ‘em. Then we’ll see who’s on top around here.”
He adjusted his grip on the Clown Car’s rim and laughed into the night.
Below, the age of All Might had just ended in a way no one had predicted.
Above, under unfamiliar stars, the age of Bowser in this Quirk-filled world had begun.
And it was going to be messy.