Prologue

"I'm sorry, Mrs Midoriya," the quirk doctor had told Izuku's mother months ago. "There's a very real chance that while your son has a quirk, evidenced by his toe joint, it's simply so subtle that we have no idea what it is. Perhaps he takes in more than the usual amount of oxygen, or his skin remains hydrated for longer than the average person. Subtle quirks are far more common than you might expect."

Subtle.

Common.

Average.

Useless.

Izuku has spent months trying to wrap his head around such words—to accept the fact that his dream of becoming a hero like All Might is destined to failure. Even at seven years old he knows how impactive the quirk doctors assessment is. To be a hero one needs a strong quirk, something better than 'the ability to breathe really well,' like the doctor had implied he probably has.

Of course it doesn't help that Kacchan and the rest of his class have more visible, useful quirks. In fact, it just serves to set Izuku apart—the boy with the quirk that does nothing. It's a fact that causes endless humiliation and earns him the pity of the boy who is supposed to be his friend. Now that Kacchan has a quirk and Izuku doesn't, everything is different. Not that kindness was ever really a quality that could be applied to Katsuki Bakugou, but his personality shifts with the new social order, with him and his explosion quirk right at the top. With Izuku right at the bottom, there was never a possibility of things remaining the same.

Pity. Exclusion. Kacchan's new treatment of Izuku holds elements of both, and it should be breaking him down—making him feel so alienated from the rest of them that he feels as useless as Kacchan is trying to imply. Instead, his words are the catalyst for his real quirk to show itself.

"You can't play with us anymore, Deku," Kacchan frowns, planting his hands firmly on Izuku's shoulders, as though he can press his point into Izuku's brain through a firm grip. His hands let off thin wispy trails of smoke from the chemical reaction of his nitroglycerin sweat. Izuku can feel the heat radiating off them as they threaten to burn the skin on his face and neck, not that Kacchan can fully control that, yet.

Izuku winces at the nickname. He shudders and shies away from Katsuki's touch, trying to squeeze his way out of the boy's tight hold. Katsuki lets go with a superior smirk and steps back. Despite his words, actually hurting Izuku has never seemed to be his goal. Izuku simply doesn't have a quirk now, so playing games with them now could end up being dangerous for the 'might as well be quirkless,' Deku—at least according to Kacchan's logic.

"This is what a real quirk looks like," the blonde boy announces, lifting his hand into the air to let his quirk crackle with mini explosions across his palm. Izuku stands against the wall and swallows his jealousy, feeling small before the potential might of Kacchan's quirk. How is it at all fair that a boy like Kacchan is able to make explosions with his hands while Izuku possibly has a quirk like 'incredibly hydrated skin?'

It simply isn't. True equality is a thing of the past. In the world of quirks, one person is not necessarily of as much value as another.

"It's not our fault you don't have a quirk," Kacchan shrugs. "But if we play with you now we have to do something boring so you don't get hurt." His red eyes gleam in the sun shining on the playground of their primary school.

Izuku frowns, trying to smother the combination of confusion and rage forming in his stomach. "I told you I've got a quirk, Kacchan!" he cries out. "I just don't know what it is yet! Why are you being so mean?"

Kacchan's face contorts, his young face still displaying a sense of superiority that should be nigh on impossible to mimic at his age. "My mum said that Auntie Inko told her that you've got a useless quirk. You can't play heroes and villains with us anymore if you don't have a good quirk, Deku."

Izuku's eyes blur with oncoming tears, but he's never been one to give up. "I can too! I'll still be just like All Might, you'll see!"

Kacchan shakes his head firmly with an annoyed huff. "Well maybe we should play right now! I'll be the hero and attack, and you have to use your quirk to fight me off!"

Kacchan is probably expecting Izuku to say no so his point is proved, but instead he hardens his expression, nods and lifts his small, flimsy fists into the air. His arms are thin and pale, his shoulders hunched as he huddles against the wall for support. There is only one thought running through his head, one feeling that overrides every other sensation. He just wants Kacchan to shut up about his lack of a useful quirk.

I will be a hero. I will.

Kacchan lifts his hands again to let off the small firecracker explosions across his outstretched palms. "Ready, Deku?" Looking doggedly determined to prove his point, Kacchan runs at Deku. No doubt he doesn't want to really hurt Izuku, but Kacchan is filled with righteous confidence—to his own mind, he couldn't possibly be wrong. If he needs to hurt Izuku to make him understand just how right he is, he will. Following through has never been an issue for Katsuki Bakugou. He runs at Izuku full pelt, nitroglycerin coated hands outstretched before him. A snarl is etched onto his face.

Izuku on the other hand pushes his back into the wall, his face caught halfway between grim determination and complete and utter fear. He cries out with a word he's never uttered before, a word that he has no idea the meaning of. It just springs into his mind and straight out his mouth like word vomit. In his mind's eye a strange creature flashes. A green caterpillar with big black eyes, a yellow underbelly and a teardrop shaped tail.

"Caterpie!"

Izuku shields his eyes with his arms, hunching low against the wall for any kind of defense against the oncoming blows. They never come. Kacchan should have been on him nearly immediately, but time seems to stretch out, and the attack never comes. Instead, Izuku listens to gasps and whispers from nearby. He slowly lifts the arms from in front of his face to see what happened.

Kacchan is tied up on the ground in a heap in thick, white string. His mouth has been tied closed as he grunts and growls and scratches at the string with his fingers. It does him no good. He's been completely incapacitated, limbs twisted together like he's on his way to becoming a human pretzel. Yet the onlookers who are gasping and whispering to each other aren't looking at Kacchan. They're looking at the giant caterpillar sitting on the ground at Izuku's feet.

Izuku blinks once. It's the same creature that had appeared in his minds in the moments before Kacchan was going to attack. What was it he had said? 'Caterpie?"

Izuku watches the creature with abject fascination. He moves to kneel down and reach for one of the yellow rings on its segmented body, but his hand never quite makes it. The creature disappears, vanishing into thin air as though it was never there in the first place. The string that had wrapped up Kacchan like a Christmas gift remains in place.

As the creature disappears, white swirls in Izuku's vision and he doubles over, pain pulsing between his temples and his ears. His knees hit the ground and he crumples, folding in on himself. Before he loses consciousness, he hears one of his classmates go running for a teacher.

"Miss! Miss! Izuku has a quirk!"

Izuku smiles even as pain explodes behind his eyes and his world goes dark.

Notes

I hope you liked this one! It kind of came out of nowhere. A guy on discord floated an MHA idea and thus this plot bunny was formed. Once I had the idea of an Izuku with a Pokemon quirk in my head, I had to write it, despite that I was working on another fic at the time. This is just kind of a prologue to set the rest of the fic up. Rest assured I don't usually post anything with so few words, and I also don't usually do prologues, but it felt right in this case.

Anyway, I know some of you probably have questions about his quirk and its limitations and stuff, and all of those will be answered in time. Suffice it to say that no, Caterpie will not be the only Pokemon in the fic.

Feel free to contact me with any questions if you have any, assuming anyone actually reads and likes this. Better yet, join my discord! It's coming up on sixty people and is pretty much dedicated to fanfiction. Theres a place for both readers and writers, readers can post fanfiction recs for others to read, writers can ask for plothelp or promote their own or whatever. It's been a whole lot of fun and I've met some really great people. I've also recently added the Pokemon discord bot which has been a huge hit. FFN is really weird with links, but it's on my profile here on the site if you're interested! Joining is really easy!