Chapter Text
“Quirk fusion?” Tomura asks. “I think I remember that… why is it important, again?”
“Do you believe in coincidence, Tomura?” All for One asks, gesturing his protégée over towards the glowing table. Holograms with images spring up; one features the USJ, which will be Tomura’s proving grounds. He’ll take a Nomu and battle All Might— chances were high that he wouldn’t win the game, but with any luck he’d knock down some of the boss’s HP, and likely take a few minions off the board, too. Hero students were pathetic wastes of life.
“Random encounters can be unnaturally convenient, yeah.” Tomura says.
“As generations pass, quirks combine through bloodlines and become ever more powerful. Garaki’s Singularity Theory postulates that because of this, one day quirks shall be so strong as to destroy the very earth they have manifested on. While that end result seems somewhat dramatic, I believe there is much to be gained from the way quirks can fuse into stronger forms— and don’t want to wait on chance for results. Some years ago, I started an experiment by gifting a special form of quirk energy to mothers who already had children and with another on the way, the expectation being that the quirks of the elder child and the unborn one would eventually be triggered to fuse, and create something new through bloodlines that were already compatible.”
“Okay,” Tomura says, scrunching his face as he parses this out. “What’s this gotta do with the USJ?”
“All three of my experiment results will be there at once, Tomura. You’ll be able to observe them— and possibly kill them, as I’ll be able to collect the fused quirks from their bodies, but I’m more interested in how such things manifest practically.”
“You want me to watch three hero kids? I’ll be busy!” Tomura complains.
“Kurogiri can do the watching. All I want is for you to make sure they are engaged in combat within his view— and I’d welcome any of your observations, of course.” All for One says.
“Sure. Which kids?”
“The most important one to watch is Monoma Neito. Officially, his quirk is termed Copy; he can temporarily borrow the quirks of others, four at once maximum, but can only use one at a time and for only ten minutes. The truth, however, is much more interesting.” All for One says. He waves his hand, and a hologram of Monoma appears, alongside that of an older girl. “This was his half-sister, Toga Himiko. Her quirk was Transform, which allowed her to take on the appearance of others for extended periods of time… provided she drank their blood. When Toga was twelve years of age, she and Monoma’s quirks were catalyzed to fuse— Toga died, and Monoma now commands a power that is his sister’s quirk as well as his own. He can copy appearance through touch, and quirk through blood, as well as vice versa— both at once makes the world’s best disguise. Truly, this result is a marvel; if you can, try and kill young Monoma, because Copy-Transform is a successful experiment that I would love to collect. Do not reduce the whole body to ashes. That would be a horrible waste.”
“Kill the blond brat, got it.” Tomura mumbles, reminding himself not to let the boy copy his quirk. That would be annoying.
“The second most successful result is that of the Tokoyami siblings.” All for One continues, and Tomura frowns at the list of students.
“I don’t see them here.” he points out.
“That’s because they are no longer Tokoyamis.” All for One says, and the holograms of Toga and Monoma disappear to show those of two UA students: Jirou Kyoka, and Jirou Fumikage. Shigaraki snarls; he remembers the bird-faced kid. “They sought to hide themselves from me when they were adopted into another family by changing their names, but it takes more than that to escape my notice. Jirou Fumikage, previously Tokoyami Fumikage; his quirk could enhance his strength but reduce his intelligence when in darkness, and the opposite in when in light. Tokoyami Kyoshi’s quirk allowed her to transform into a a being of shadow. When the catalyst occurred, Kyoshi’s soul was ripped from her body along with her quirk vestige, and both were permanently bound to Fumikage and his power— now, his sister hides as a sentient quirk under the name of Dark Shadow, and is affected by darkness and light instead of he. She is a powerful quirk, and once I take it, I can divest Dark Shadow from Kyoshi’s soul and have only a pliant vestige to command. Try and kill this one if you can as well— Dark Shadow is a quirk of enormous potential. Besides, I’m sure you’d like your revenge.”
“How does Kyoka come into this?” Tomura asks. He doesn’t remember another girl being involved.
“Adoptive sibling. She’s not important.” AFO says, and then changes the hologram once more, revealing a boy with red-white hair. “The final and least successful experiment is that of Todoroki Shouto. He has not fused with any of his siblings, perhaps due to a lack of emotional interactions, which I’ve noticed was what activated the first two fusions. Choosing Todoroki Rei as a subject was a gamble on my part, one that so far has failed. The Todoroki family has so far abounded with possible fusion catalysts, but not a thing has come of any of them. Is it because Touya left the family before Shouto was grown? Because Fuyumi’s ice is too similar to the ice Shouto already holds? Because Natsuo is quirkless? Nevertheless, the sheer power inherent in Shouto means that should a fusion occur, it will doubtless be brilliant. Therefore, you are forbidden to kill him. Do you understand?”
“Yes, Sensei.” Tomura says, eyeing Endeavor’s son suspiciously. “Maybe he’s already a fusion? Since he has a dual quirk?”
“His power is a single quirk with two aspects; that’s four times the level of your quirk, actually, but not in the least a fusion.” AFO says, with a small laugh.
“Rude.” Tomura mutters.
***
A Few Months Earlier
Katsuki had burnt Izuku’s notebook. Again.
“That wasn’t very nice, Kacchan.” Izuku says; thankfully, only the cover was charred, and all his notes on heroes were safe. School had ended, and Katsuki and his cronies were the only other people in the classroom.
“You’re going to try and get into UA.” Katsuki says. It’s not a question, but a statement.
“Of course I am! I’m sure we’ll both get in.” Izuku says, and Katsuki slams his hand down on the desk.
“Stop following me.” he says. “You’re always trying to one-up me, Deku, and it’s getting really annoying— so just fail the entrance exam, okay? It’ll make things easier for both of us.”
“No.” Izuku says, just like every time Katsuki tells him to give up.
“Thought you’d say that.” Katsuki huffs, standing straight before giving Izuku the middle finger with a grin. “Fly as high as you can, Deku, you’ll only hit the ground harder when I knock you down!”
“Only if you can catch me.” Izuku retorts, shoving his notebook in his bag and standing up before swinging the whole thing over his shoulder.
“I’ll catch you all right—“ Katsuki growls, lunging forwards; Izuku dodges his hands, weaves out of the way, and topples backwards out the window.
“That’s cheating!” Katsuki complains; for the wind and the sky are Izuku’s home. The air is solid beneath his steps, and he can shoot air from his palms and feet that allows him to fly at incredible speeds— Katsuki can fly too, with Explosions, but not nearly as well as Izuku. There aren’t many quirks that fly better than Air Repulsion. Izuku walks to the ground on a set of invisible stairs; he doesn’t want to get in trouble for quirk use, and although using the wind to shoot himself forwards is tempting, he resists the urge. Hopefully he’ll still be able to reach Mt. Lady’s debut in time.
It’s only on the way back home from Mt. Lady’s fight that Izuku comes across something really interesting. The sound of shouting, as well as a great black plume of smoke rising into the air, naturally attracts his attention; pushing through a gathering crowd, Izuku is horrified to see a boy trapped within a villain made out of sludge. Explosions fly everywhere, useless against the sludge, but setting the surroundings on fire, and that’s Kacchan and he’s dying and no one is doing anything—
Izuku finds himself running at the same time as someone else breaks from the press of the crowd.
He surges forwards at an incredible speed, air flying from his feet and hands as he leaves the ground; he feels the lightest of taps on his shoulder, and suddenly two wind-powered fists are driving at full speed into the sludge, exploding it apart and begging to free Katsuki, who struggles, screaming. as he tries to escape. The sludge begins to reform, but then something glorious happens— All Might himself descends from the sky, and knocks the sludge away from all of them with a punch so strong that it begins to rain, and the fire clears away.
“Kacchan!” Izuku cries, and his friend staggers to his feet, coughing.
“Shove off.” he says. “Both of you.”
“YOU DID WELL, YOUNG BOYS.” All Might says, and Izuku makes an eep! noise, feeling a gigantic hand on his shoulder.
“Th— thank you?” Izuku squeaks out. He glances over to the other person who had helped him save Katsuki; a boy with yellow hair that sports the design of a black lightning bolt. How had he run with equal speed as Izuku, who had been leaping with the wind?
“Hey, All Might.” the boy says.
“Oh dear, reporters.” All Might says, and as the press begins to crowd around him, suddenly he’s gone as soon as he had arrived. Izuku blinks; that’s a lot of stealth for someone his size.
“Kacchan, are you okay?” Izuku asks, but Katsuki is running off to who knows where, too.
“Kind of ungrateful.” the boy beside Izuku says.
“Kacchan is always like that.” Izuku says.
“Friend of yours?”
“Yes.”
“Need another friend?” the boy asks. Izuku stares at him, and he smiles, gesturing towards himself. “A better friend. The name’s Kaminari Denki.”
“Kacchan is a great friend! But yes. And thank you for helping me save him.” Izuku says.
“Come on, let’s get out of here.” Kaminari says, and the two start to make their way away from the rest of the group.
“I wish I’d been able to get All Might’s autograph.” Izuku pouts.
“You’re a hero fan, then?” Kaminari asks.
“I’m going to be a hero. Just like All Might.” Izuku says, and Kaminari laughs.
“Good luck.” He sounds like he means it. “My friend is going to be a hero, too. What’s your quirk?”
“It’s called Air Repulsion!” Izuku says, demonstrating by stepping a few feet up in the air. “I can also move really quickly with it, too.”
“My quirk is Electricity.” Kaminari says, holding up a hand; yellow energy crackles in his palm, lashing and flashing.
“That’s amazing!” Izuku says. “You don’t want to be a hero?”
“Eh.” Kaminari says. “Sometimes.”
“Why only sometimes?”
“It’s a long story.” Kaminari sighs, and then he freezes, skidding back behind a wall and dragging Izuku with him before peeking around and peering into a shadow. “Is that… All Might?”
Izuku squints, looking at the tall figure, but then the evening light changes in direction, and the All Might-like figure is revealed to be someone significantly skinnier. “Oh. Too bad.” Both boys watch as the skinny figure glances around surreptitiously, and once he’s found the coast clear, he transforms in a puff of smoke. Into All Might. And then he flies off.
“Did he just— was that All Might?” Izuku asks. What had he just seen?
“All Might can shapechange?” Kaminari asks, eyes sparkling with a strange fervor. “No wonder he’s been able to keep a secret identity.”
“We shouldn’t tell anyone.” Izuku says. Kaminari looks at him. “I don’t know why All Might keeps this secret, but it has to be for a good reason.”
“You think All Might could be in danger?” Kaminari asks. Izuku shifts where he stands— the idea of All Might as fallible is an anachronism.
“Regardless, it wouldn’t be right. A secret identity is something private. If he doesn’t want to show his true self to the world, who are we to make him?” Izuku asks. He can’t help but wonder, though… if the All Might the world saw wasn’t the real version, what was? What secrets did Izuku’s idol hide?
“You’re right.” Kaminari says, with a wry smile. “I do wonder, though… what’s out there that All Might needs to hide from?” Izuku feels a chill. He hadn’t thought about it like that. “It’s getting late out— see you tomorrow?” Izuku and Kaminari exchange phone numbers; it’s a good thing that he’s made such an interesting friend, but did such a terrifying mystery have to be a part of it?
***
“You’ll never believe who I met today.” An apartment door slams shut, and Kaminari Denki looks up from his book to a reflection of his own face.
“All Might?” he asks.
“How did you know?” Monoma Neito whines, face-planting dramatically into the sofa. The points of his yellow hair are only just visible over the pillows.
“It was on the news— I saw you and some other guy fighting a sludge villain. How’d it go?” Denki asks. It might seem strange, but he’s long since gotten used to seeing double; he and Neito shared an identity through judicious use of the Copy-Transform quirk, and therefore Neito never looked like himself.
“I made a new friend. He’s planning to be a hero, you’ll like him.” Neito says. Denki was going to apply to UA, but Neito had no such dreams— not since his past had dashed those hopes. Instead, he was the vigilante known as Phantom Thief (which Denki also was, sometimes), and Neito swore that one day, he would defeat the villain who had killed his sister. Unfortunately, considering said villain was the monolith of power known as All for One, such a day was rather far off.
“And?” Denki asks, because Neito’s emotions are obvious to him, and it’s quite clear there’s more to be told.
“All Might shapeshifts, Denki. Since his real name is unknown… he’s got to have a secret civilian identity, and I know exactly why.”
“All for One?” Denki asks.
“All for One.” Neito confirms.
“Don’t tell me you’re going to try and stalk All Might.”
“I’m going to try and stalk All Might— hey!” Neito yelps, because Denki has thrown a sock at him. “If there’s anyone who has an idea as to what AFO’s been up to, it’s him!”
“You plan on getting arrested?” Denki asks. “Or worse, on getting me arrested?”
“If I could get some of his blood, then I could copy his quirk.” Neito says. Ever since his quirk had fused with Himiko’s, he could copy quirk and appearance through both touch and blood; these days, Neito wore a bracelet with an infusion of Denki’s blood, so that it was constantly against his skin. In this way, he could wear Denki’s appearance and quirk permanently; it just wasn’t convenient to drink a cup of Denki’s blood every day, but they did that too, sometimes. Copy-Transform instilled in Neito somewhat of a hunger for blood, and although he often bit those he fought, Denki never minded offering.
“Have you ever seen All Might bleed?” Denki asks.
“…no.” Neito says. “Fine, I’ll just touch-copy. Even a few minutes of that quirk sounds like great fun.”
“Try not to die.” Denki says.
“I won’t die.” Neito huffs, nettled.
“I know.” Denki says. Three years previously, Neito had saved Denki from villains who had been using him as a generator, and the two had stayed together ever since. Since overuse of Denki’s quirk had a terrible effect on his braincells, such abuse of it hadn’t left him with much memory of his past; Denki really had barely any idea what his life had been before his kidnapping. The reason he wanted to be a hero was to prevent what had happened to him from happening to anyone else, to get rid of quirk trafficking, which was a danger to people with conventionally useful quirks. As for those with ‘villainous’ quirks… Denki looks over at Neito. His friend had saved him, but there hadn’t been anyone there to save Neito, or his sister. If Denki could become a hero, he’d do his best to make sure no one was abused for their quirk ever again.