Chapter Text
It had finally worked. Countless years Hisashi Midoriya attempted to pass on his legacy, but to no avail. No matter how many times he tried NONE of his quirks passed on to his children, all ending up quirkless… until now that was. In his hands he held his newborn son, Izuku Midoriya. Running some initial tests on the boy he found that Izuku’s mutant quirk also had a mutated variant of AFO. However, at such an early stage in the boy’s life it was impossible to tell how it worked.
At age four, Hisashi took Izuku to see Dr. Ujiko to find out what his quirk was, the wings and tail and eyes and teeth were a given part of his quirk. He had them since he was born. The wings didn't have any feathers, but the skin covering them was hardened and green like his hair, so was his tail. His eyes were slitted bright green like cat eyes. His teeth were more akin to sharp jaws. To Hisashi he looked like a little devil, and when he grew up, he would make an excellent supervillain, a sight to strike fear in to all who opposed him.
‘If only Izuku wasn’t so fascinated with heroes,’ Hisashi thought to himself. It was true, ever since Izuku learned about heroes he had wanted to be just like them. The most infuriating thing was who his son’s favorite hero was, Nana Shimura. ‘Of all the heroes, it had to be my Arch-Nemesis?’ It didn’t matter though, eventually his son would see things his way. With his mutated AFO quirk it was inevitable. He would feel the hunger for quirks just like him, and when the heroes he so idolized get in his way. His hatred for them would grow fast.
Izuku went through the doctor's many tests. The x-rays showed that he was starting to grow horns. A couple tests proved that the skin on his wings and tail were thicker than the rest of his body. The strangest thing however was that Izuku's quirk was still "Waking up". Part of it was active, but it seemed it would take longer before the remaining elements kicked in.
Hisashi registered Izuku’s quirk as Sturdy Wings and drove back home.
Izuku left to meet up with his only friend Katsumi Bakugo the next day, and mentioned he went to see a quirk specialist.
"Like you need to," she mocked, "You've had those wings your whole life. You already know your quirk."
"Kind of," Izuku replied.
"What do you mean?" she asked confused.
"According to them my quirk is still 'Waking Up', the wings, tail, eyes are only part of my quirk."
"Any idea what the rest is?"
"Well I'm growing horns apparently."
"What? Let me see," she said bringing his face down and feeling his head, "I don't feel anything."
"Neither do I, but the x-rays said they are starting to form."
"We'll look so cool together. Fighting side by side as heroes."
"Yeah," Izuku replied excitedly.
Oh, the ignorance of youth…
It wasn't until he went through puberty that his quirk started becoming active. During this time, Hisashi’s underlings warned him about how close Sir Nighteye, sidekick of Nana Shimura, was getting in his investigations. Hisashi had to leave his wife and child and moved to America. He would return someday to guide his son, but he had to keep the heroes away from his legacy. He left behind Garaki, Kurogiri and Tomura to watch over the boy from afar.
Izuku however, was not happy. First his dad left, and now his quirk was making him a…
Izuku’s horns were about three inches long now. His nails also hardened into black claws. Katsumi said they made him look cool.
She was the only one to think so at their school. With his mutation everyone else agreed that Izuku was some demon from hell, and while he knew he wasn’t a demon, he started to feel like one. His quirk had begun changing him in ways he didn’t expect. But he was fine, right?
On his 15th birthday, Doctor Ujiko made a visit to the Midoriya Household. Izuku wondered what he was doing there, to which the old man replied, “I’m a good friend of your father. He told me to look after you, and I figured you would want your quirk re-evaluated so you can get into the right school.”
Inko gave him a thumbs up and said that she needed to stop at the store to get groceries to make dinner.
Izuku was… broken when he came back from his visit with Dr. Ujiko.
Quirk: Incubus (Changed by Physician)
This confirmed Izuku’s greatest fear. He was a demon. He locked himself in his room after that, and sulked most of the day.
“Deku!” Katsumi called out as she pounded her hand against the door.
“Kacchan?”
“Open this damn door before I blow it open!” she shouted with anger.
Sighing to himself, he went and opened the door to be met by Katsumi’s death glare.
“Good!” she said before walking in and slamming the door shut, “Sit!” He complied. “Now tell me what the fuck is wrong with you?” Izuku didn’t say anything just handing her the file he got from his visit to the doctor. She read the three lines sticking out and asked, “So? Your quirk name changed. Big deal.”
It took Katsumi nearly half an hour to convince Izuku that he could still be a hero with his “demonic quirk”. After he had calmed down enough, he went to go help his mother fix dinner since that usually helped calm himself.
As soon as Izuku left the room however, Katsumi couldn’t help herself, being curious about the Incubus quirk. She opened his file and as she read it her face began to blush.
Patient Name: Izuku Midoriya
Quirk Type: Mutant
Quirk Name: Incubus (Changed by Physician)
Description of Quirk and its Effects:
Quirk gives patient wings, horns, a tail, claws, and alters his eyes. Skin of wings and tail are thicker and green in pigmentation. Horns and claws are black. Bright green demonic eyes make it easier for him to see in the dark. Enhanced strength, speed, and stamina. Claws are easily sharp enough to cut through skin.
Quirk seems to have effected patient’s sexual characteristics. Patient has a penis measuring 9 In in length and 5 In in girth when flaccid and 11 In in length and 6 In in girth when erect. The levels of semen production are higher than the average person as well. The quirk also seems to give patient an increased libido.
There are still a few things about the patient’s quirk that are unknown or have yet to make themselves known.
‘That’s enough of that,’ Katsumi thought to herself closing the file and putting it back where she got it. Over the years Katsumi had several times fantasied about Izuku and reading this was not going to calm her down any. She wanted him to want her, but Izuku was too shy to try anything.
That was until the day of the incident.
Izuku and Katsumi were taking their time heading back to Izuku’s after hitting the arcade when a manhole cover exploded. A sludge villain popped out and immediately started attacking Katsumi.
Seeing this, Izuku tried desperately to free his friend from the sludge. He watched as the sludge monster began to take control of Katsumi’s form, the panic clearly showing in her eyes. As she struggled against the villain, she let out a few explosions in desperation, “Looks like I grabbed a good skin suit, I’ll keep you alive for now.”
Something inside Izuku snapped.
Izuku was moving, he was on autopilot wildly attacking the only part of the sludge villains form he thought he could damage, the eyes.
“Let her go, you BASTARD!” Izuku shouted he was moving like a feral animal.
“Hahaha, you really think you can do anything to me?” the villain mocked before leveling Katsumi’s hand and using his control of her fired off an explosion, which Izuku blocked with his wings. It hurt like hell, but he would die before he stopped trying.
Suddenly the manhole cover exploded again and out popped the number one hero Nana Shimura.
“Never fear, for I am here!” she shouted before moving to help the two teens. She was quick, aiming a punch at the slime villain, not punching him, but the air. The force of the blow was enough to free Katsumi and dissipate the villain’s form, effectively knocking him out.
“Sorry, I lost track of him in the sewers and he managed to get to you,” she apologized, “Are you two okay?”
“I’m fine,” Izuku said holding Katsumi securely in his arms. Once she was freed from the villain Izuku wouldn’t let go of her. Normally Izuku would’ve been excited to meet Nana in person as her number one fan, but his mind was too preoccupied with the blonde in his arms. His best friend, his first and only crush, was almost taken from him.
“What about you are you okay?” Nana asked Katsumi.
Katsumi merely nodded shocked, enjoying the feeling of being in Izuku’s arms, although she would never admit it.
Izuku gave the hero a thanks for saving them before he flew himself and Katsumi back to his house. He landed just outside of his house and carried Katsumi in sitting her on the couch and promptly passing out.
Meanwhile in Izuku’s Mindscape
Izuku found himself in a pitch-black room, another him looking his way.
“Who are you?” Izuku asked.
“I’m you,” the copy replied, “Or rather I’m your quirk, Incubus.”
“How come I’ve never seen you in my dreams before?”
“Because I wasn’t fully developed. Now I am… well almost. Izuku it’s time for us to join.”
“What does that mean?” Izuku asked confused.
“You need to unlock the last part of me, once that happens, you and I will be one.”
“And how do I do that?” Izuku asked.
“By taking Kacchan into our bed and fucking her till she’s seeing stars.”
“Well, that was pretty graphic…”
“I’ve been waiting to fuck her for years, but you don’t seem to get it. We require sex for sustenance. We can get by on food, and still be ‘healthy’, but unless we fuck something we are going to DIE! Why do you think you’re so damn horny all the time?”
“But what if she doesn’t want…”
“I know she wants us,” Incubus said, “You may be ignorant to it, but I can smell her arousal when she’s around us. She wants us, and we want her. She nearly died today because we weren’t strong enough.”
“What will even happen when we join?”
“I…” Incubus pondered, “I don’t know. I only know what I can do, and how I can do more, not what I will be able to do after, but it has to be better than this. She nearly died because we are too weak… we can’t let that happen again.”
Meanwhile
Katsumi had managed to get Izuku into his own bed. She looked down at Izuku, a blush forming on her face thinking about the ideas she had as he held her. True, he hadn’t been the one to save her, but he tried with all his heart, and ‘That deserves some reward, right?’ she reasoned with herself.
Before she could do anything however, Izuku began to stir. His bright eyes blinking as he sat up. Wondering when he had gone to sleep. Then his mind went to the dream he had, and he realized he was on his bed, and Katsumi was standing right in front of him. At first, he began to panic before he realized he didn’t rape Katsumi in his sleep.
“Are you okay Izuku?” Katsumi asked worried. After all, he did just faint on her.
“Yeah, I’m…” Izuku began to lie before he realized she was going to find out at some point and if he didn’t tell her… he didn’t want to imagine her wrath. “No, I’m not.”
Izuku patted the space next to him on the bed and explained the dream he had, and his own feelings, and how ashamed he felt for not being able to save her when she needed him.
Izuku was pleasantly surprised when Katsumi pulled him into a kiss. “Stupid Deku,” she said chastised as she broke for air, “Do you know how much time you could’ve saved us both if you confessed to me years ago? Why does it take a near-death experience to get you to confess?”
“I’m sorry Kacchan,” Izuku apologizes.
“Hmmm…” Katsumi says, “I’ll forgive you if you do a favor for me.”
“Anything!” he said sincerely.
“That’s what I like to hear,” she smirked. She quickly discarded her skirt and panties revealing her pussy to Izuku who immediately covered his eyes.
“Kacchan?! What are you doing?”
“Collecting on that favor,” she said grabbing Izuku by his horns and pulling his face to her sex, “Make me cum with your tongue and I might forgive you for being an idiot.”
Izuku’s mind couldn’t process it, but his body sure could as he instinctively began to eat her out.
“Oh god!” Katsumi shouted, “Right there!”
Encouraged by her Izuku began to fuck her with his tongue, loving the taste of her juices as he did so.
“Oh? What do we have here?” she said looking down at the tent in Izuku’s pants, “You getting off on me riding your face?” Izuku couldn’t do much but moan himself, the vibration going straight to her pussy as he continued working it. Soon enough Katsumi moaned as her orgasm overtook her, finally letting go of Izuku’s horns. “Okay,” she said.
“Okay what?”
“I forgive you,” she said, “ Now get on the bed.”
Izuku did as he was told sitting up on the edge of the bed. Katsumi got down on her knees in front of him and unzipped his pants, pulling them down and pulling down Izuku’s underwear with them. His cock swung up as it came out of the confines.
“Kacchan, you don’t have to…” Izuku began to say but was cut off when he felt her tongue against his shaft.
Katsumi stopped her act and looked up at her best friend, “Deku.”
“Yes?”
“Stop talking,” she said as she brought her mouth to the head of his dick and began to suck on it. She couldn’t get it all, but damn was she going to try. Izuku was in heaven as Katsumi worked on him. He started to feel the urge to cum rise, but Katsumi stopped him, gripping his cock in her hands, not moving a bit as he began to calm down, “Don’t think you’re going to just sit there. If you want to cum, you’ve got to work for it.”
Izuku was stunned silent as he saw Katsumi take off her shirt and bra leaving her now naked before him. She got on here hands and knees on the bed presenting herself for him, but Izuku didn’t move worried that all this was just a dream that would end as soon as he tried anything. “Well?!”
“Well what?”
“Dammit Deku!” she shouted, “How much more obvious can I make this? Fuck me!”
“Are… are you sure Kacchan? I don’t want to hur…”
“Don’t give me that bullshit!” she shouted, “I want this as much as you do, probably more!”
‘That’s impossible,’ Izuku thought to himself as he brought the tip of his cock to her entrance and proceeded to push into her. He was stopped by her hymen.
“Really? I can take it! Give it to me!” she shouted.
Encourage by her Izuku pulled back a little before pushing in as much as he could through her hymen, sinking about 4 inches into her tight pussy.
“Fuck!” Kacchan shouted, ‘It hurts so good.’
Izuku waited a minute or so until he thought Kacchan was adjusted before backing out a little and sinking a bit more in. He slowly worked in and out of her going deeper inside until her encountered her cervix.
By this point Izuku had 3 In left. Katsumi noticed his hesitation and decided to push back into him causing his cock to push against her cervix and Katsumi to cry out in pleasure.
“That’s it, fuck me Deku!”
And so he did. Every time he pushed in; he hammered the entrance of her cervix. After 10 minutes of this however, Izuku broke through. His cock pushed through and into her cervix sending her over the edge.
“Oh fuck me, I’m cumming!” Katsumi yelled out from the overwhelming feeling.
Izuku couldn’t stop now, hearing her climax egged him on as he proceeded to pound into her more. “Kacchan! I’m going to cum!”
“Pull out! You can’t get me pregnant!” Izuku tried and managed to pull out before his cum shot out and coated Katsumi’s back. ‘Good thing he didn’t pump this into me,’ Katsumi thought before feeling Izuku rub his erection against her ass, ‘The fuck?’ “Deku, you’re still hard?”
“Usually need to cum a few times before I’m done,” Izuku said before turning Kacchan over onto her back.
“Idiot, now you’ll have to do laundry.”
“Who cares about the sheets,” Izuku said claiming Kacchan’s mouth as he lined up and sinked his cock once more into her pussy.
Katsumi came a total of seven times. Izuku came three times, by the time of his final ejaculation Kacchan’s front AND back were covered in his cum, but when he finished he lost himself in her and came deep in her painting her walls with his cum. Kacchan wanted to complain, but had been fucked into exhaustion.
Meanwhile
Nana Shimura was back at her agency checking in on her sidekick, Sir Nighteye.
“Mirai,” she said gaining her sidekick’s attention, “How goes it on the search?”
“Not well,” he responded, “Trail is still cold, and I haven’t tracked down his ‘project’ either.”
“You know that was just a theory, right?” she asked.
“True, but when Nezu proposes something, it’s best to assume it’s correct.”
The two of them thought back to the conversation they had with Nezu five years ago, when AFO suddenly vanished.
Flashback
“It sounds to me like he’s fled the country,” Nezu responded, “He probably caught wind that you were on his tail and ran, but the fact he did so is troubling.”
“Why is it troubling sir?” Nighteye asked.
“Why run?” Nezu asked, “AFO has bested every holder of OFA since his own brother, yes?” Both Nana and Nighteye nodded. “Then why run when he knows you are coming to him? It makes no sense, unless he’s planning something big.”
“You’re referring to his old cases?” Nighteye guessed.
“Indeed,” Nezu responded, “Several women and newborn children dead over the course of seven years. The only connection between them being the father’s DNA. What do you think he was trying to do?”
Nana couldn’t picture AFO being with ANYONE let alone eight women, and for what purpose? He didn’t care about anyone.
“A legacy? Breeding a second holder of AFO?” Nighteye guessed.
“Exactly,” Nezu said, “I’m guessing the reason he stopped, is the same reason he’s fled the country. He succeeded and doesn’t want us to know about the second holder, until he’s ready to use them.”
Flashback Over
“To be fair, can you imagine AFO as a family man?” Nana joked causing the lanky sidekick to chuckle.
“No, but it puts my mind at ease to check, just in case,” he said, “So, how was your day today?”
“Oh, not much happened,” Nana replied, “Lost track of a villain, but found him harassing some teen couple, took care of him. The usual.”
“You know, if you let me use my quirk on you, you wouldn’t have lost the villain in the first place.”
“Yeah, but remember, no using your quirk on me. So, how did Toshinori do in training today?”
“His body is adapting to the new quirk exceedingly well,” Nighteye responded.
“That’s good to hear.”
“I still think Mirio would have been the better choice,” Nighteye quipped.
“My quirk, my decision,” Nana replied.
Meanwhile
Izuku found himself once more in his mindscape. He looked around and couldn’t find his other self, ‘Does that mean I’m alone?’ he asked himself.
“Don’t count on it,” he heard Incubus say from behind him. He turned to find his twin sitting on a chair, his cock being sucked by a Kacchan clone whose hands were tied behind her back. “Oh yeah, our first slut,” Incubus said as “Kacchan” sucked him. “You never forget your first, and neither will she. Isn’t that right slut?”
“That’s not really her though,” Izuku pointed out.
“This is her quirk, Explosion. When you came inside her, she appeared, giving us access to her quirk.”
“Crap!” Izuku shouted, “Mom’s going to kill me, and then Kacchan’s going to bring me back and kill me again.”
“They’re not going to kill you.”
“I came inside her, what if she gets pregnant, she won’t be able to finish UA and it will be my fault.”
Incubus stopped Explosion and gestured over to Izuku. She seemed to get the message as she walked over to Izuku and got down in front of him and inhaled his cock as Incubus got behind her and started fucking her.
“Oh, that feels good,” Izuku moaned.
“You need to learn to calm down,” Incubus said as he thrusted into Explosion, “Kacchan isn’t pregnant.”
“How do you know?” Izuku asked between moans.
“If we wanted her pregnant, she would be. Good thing we can choose that considering how much we pumped into her. Though I must say the thought is enticing,” Incubus began, “Fucking our little firecracker until she’s carrying a couple brats.”
“No!” Izuku yelled, “It would ruin Kacchan’s dream of being a hero if she got pregnant now.”
“I didn’t say now,” Incubus said, “We can wait on pumping her full of kids. Especially if she looks anything like Aunt Mitsuki when she gets older. Though, we could always try to fuck the original blonde bombshell too.”
“That’d be like fucking mom."
“You can’t lie to me Izuku, I’ve been here since we were born. I know every dirty fantasy you’ve ever jacked off to… Though, fair enough, maybe not Auntie, I doubt we could handle both her and Kacchan.” Izuku sighed in relief, he was getting through to Incubus. “At least not right now.”
“Kacchan would be devastated if I did that with her own mom let alone another person.”
“Oh?” Incubus asked, “You really think that Kacchan is enough? Spoiler: She’s not. I have a built-in hunger to collect women and to fuck them, and while you are still technically the one in control, even you will feel the hunger when it gets too high.”
“Even if what you say is true, Kacchan would never go for it.”
“Maybe not right now, but with sex, things change. You need to put our little firecracker in her place, once you do that, she’ll be more than happy to be in our harem.”
“So what? I’m doomed to seek out new women for all time?”
“No, just make sure you have sex often enough to placate me.”
“Are you placated?” Izuku asked annoyed.
“For now? Yes. Though we should probably get Explosion to show you how to use our new quirk.”
“Yeah…” Izuku said, “I’m still not sure how we’re going to explain gaining a quirk via sex.”
“I don’t know,” Incubus said, “We could just keep it to ourselves until the time is necessary to use it, but the physical changes are going to be impossible to hide.”
“I guess it’s something to consider, but let’s go ahead and learn how to use Explosion.”