Okay, so I’ve seen a handful of bnha fics/ideas where someone gets deaged, but I’ve yet to find a “Katsuki gets deaged” fic that I think really embraces the full potienal of Chaos Gremlin With Access to Near Unlimited Nitroglycerin Is Unleashed. I’ve got some ideas to fix that.
What if he got deaged, but under dangerous circumstances?
Maybe after capturing Katsuki for a second time, Tomura has a shiny new plan for converting him to villainy. Clearly, the issue was they didn’t get him young enough. He needed to be younger and not brainwashed by hero society, so he could truly understand where he belonged. Using Quirk Fuckery, they deage Katsuki to like 6-7. If they did their research and plan it right, they could convince him that they recused him from some dangerous situation. Kid Katsuki buys it, and they convince him he’s being raised by them to be a special hero. He has to be very careful though, bad guys are trying to lie to him to take him away from them. The LOV is then running around trying to raise this little kid, keeping him in the dark about their true intentions and mission, all while keeping him away from the heroes.
Eventually, Izuku manages to reach Katsuki. Using facts from their childhood, secrets nobody else would know, and showing him proof they’re in the future, Izuku is able to convince Katsuki to come with him. Unsure, but trusting his childhood friend who is now LARGE and has a COOL QUIRK, Katsuki and Izuku escape back to UA. At UA, all his supposed friends sequel over him for a bit, a bunch of weird adults ask him a lot of questions about the people who were taking care of him, and then they finally reverse the quirk effects.
Kid Katsuki is deaged by Tomura hoping to convert him to a villain, but he doesn’t buy that shit for even 1 (one) second. He can smell a liar a mile away and he has even less self-control and self-preservation than Big Katsuki does. After about a minute of hearing Tomura spew bullshit, he attacks them and manages to get free.
The problem is, Katsuki has no idea what’s going on or who he can trust. He does figure out that he’s in the future, and he’s able to guess was a quirk. Peaking through his pockets reveals his dorm keycard that lets him know he’s a student at UA. Great! All he has to do is get back there and someone will know how to help him reverse this quirk.
Only… he’s on the other side of Japan from UA. So little Katsuki embarks on an adventure to return to UA, all while keeping away from both the LOV, and his poor teachers/classmates who he doesn’t realize are his teachers/classmates. As far as he’s concerned, his never seen those people before in his life, and the villains tried to say they were on his side too. Using his own wit, small size and explosions, he makes his way home.
Katsuki is badass little 7 year old, and in the end he dodges a final attack by the LOV and makes it to UA in the nick of time. Using his ID card to get back into the school, he consults a map, and walks himself right over to the nurse’s office to ask for help with getting big again. Recovery Girl is out, so he waits there for a few hours until someone finally finds him sitting outside her office, playing games on his phone. For the past few hours the heroes had thought the LOV’s attempt succeeded or killed him, because he completely disappeared off both group’s radar.
Aizawa has been losing his mind with worry, totally convinced he’s lost his student again and it might be for good this time. Then his phone rings and it’s Recovery Girl calling to let him know that Katsuki’s been at UA for the past few hours and he’s totally fine. Restoring him to his proper age is easy enough, but everyone is now 10% more afraid of him because wtf he was like 7 at most. 7-year olds aren’t supposed to be able to do all that shit. Izuku is the only one whose not even the least bit surprised, and honestly wasn’t that worried about kid Katsuki.
There’s also some really, really good angst hiding in there if they question Katsuki before he’s made big again. Kid Katsuki escapes from the LOV all on his own and finds his way back to UA. It’s very impressive, but his teachers are baffled. Why didn’t he just go to the police? Why didn’t he trust the pro-heroes who were trying to save him? Why didn’t he go find a pro-hero to help?
Kid Katsuki is confused and upset by these questions. Why would anyone be coming to save him? He’s 7 and he’s got a strong quirk, he’s supposed to be able to take care of himself. Other people shouldn’t need to waste their time trying to protect him.
It lets them see a glimpse of just how deep Katsuki’s difficulty in relying on others runs.