Actually, now that I’ve talked about my headcanon that Katsuki was kidnapped several times as a child, let me talk about a complete random scene/story arc inspired by that and the fact that Katsuki + Izuku + Shouto are all interning with Endeavor now.
Overhaul breaks out of jail and gets his arms back somehow. He’s gone quite a bit nuts. A lot nuts. He’s surpassed ‘focused villain trying to do one thing that he sees as right’ to more of a ‘just want to watch the world burn’. To that end, he sets about getting a team together to catch a certain group of meddling heroes, and to rekidnap a certain child.
A second hideout raid of sorts is planned and goes down, only this time, it was a trap. Izuku/Shouto/Endeavor/Hawks/Kirishima/Tamaki/Fatgum/Tsuyu/Ryuko/Ochako were on the raid team and were caught. Aizawa who was watching over Eri while she had a playdate with Tsuyu’s younger sister, Satsuki, are all also captured. Overhaul had a very specific team set up, knew about them in advance and planned out counters for each person. Alongside that, he used his quirk to create a giant beast like robot that’s made of metal able to withstand even Deku’s punches and Shouto/Endeavor’s flames. Said robot is roughly modeled/made to take on the LOV’s nomu, but non-organic. Notably, Katsuki wasn’t on the hideout raid team (or aware of the raid), because he had a Obligatory Family Trip planned on the same day and so wasn’t at the internship then.
Izuku had managed to put in a distress call before he was taken down, but all the heroes + victims were moved to a different location afterwards in an old long abandoned hideout in the middle of the woods, and there’s about no chance of anyone tracking them down any time soon.
So that leads us into the main scene. The heroes are all captured/restrained up near Overhaul whose ranting on about using Eri to destroy the world/destroy quirks once and for all and then rule over it with a robotic army which is the only thing he considers “clean” anymore. Meanwhile, Eri and Satsuki are down in a different location in a cell of their own (to prevent the heroes from comforting the children), and there’s a camera system in place so the heroes can see the helpless children.
Overhaul demands Eri be brought to whatever Evil Machine he’s devised, and one of his goons goes to get her, but Satsuki fights back against the goon and actually does a pretty damn good job of it. Which leads to Overhaul demanding that the goon kill her.
There’s nothing any of the heroes can do. Satsuki fights back as best she can, as does Eri, but they’re both only 6 years old and Eri’s quirk isn’t working. They struggle, but it’s looking hopeless, and Aizawa tries to tell Tsuyu to close her eyes because he knows what’s about to happen next.
And then the entire dungeon the two girls are in shatters.
Everything is chaos for the next minute as Overhaul tries to figure out what the hell just happened, getting his cameras back in order until finally he gets a visual and contact with one of his goons just before they get taken down and it’s Katsuki.
He’s in a flannel, regular pants and his combat gloves, very clearly confused/pissed off/not prepared for whatever the hell is going on here, and it takes them awhile to figure out what’s going on.
As it turns out, Katsuki has been hiking a trail near this hideout since he was 4 years old. His family drags him up to a nearby location to visit some extended family, he has 0 interest in doing that, so he goes and hikes/camps along a trial instead. Every year he hikes this fairly long trail, and every year he sees this weird abandoned building that he’s gone to explore a few times, and every year the first thought in his mind is ‘Man, that place looks exactly like a villain hideout’.
Then this year, he comes up on it, minding his own business with his headphones in, and he sees the building active again with people with weird masks running around in it, and he’s got a super bad feeling in his gut that just slams into him and he goes ‘Alright, fuck it.’
So now Katsuki is here, he grabs the kids and gets them to a semi-safe location, getting info from them and trying to understand what’s going on. Once he gets it, this turns into a game of him keeping the kids safe from Overhaul, taking down his goons as he goes and working his way towards where the other heroes are. Only, we’re going with the aforementioned headcanon that Katsuki has been kidnapped a bunch of times as a child and never realized that wasn’t normal. This leads to the heroes watching him on the cameras with an increasingly pissed off Overhaul as he walks the two children through how deal with being kidnapped as if these are normal everyday life skills.
Overhaul really, really wants him dead, but unfortunately his team was handpicked to counter the heroes who he’s already captured, and he wasn’t counting on Katsuki showing up. Katsuki’s quirk is flexible and very destructive + Katsuki’s combat skills means he’s pretty much a worst case scenario for Overhaul. Even worse, Katsuki successfully took down the com lines so there’s no communication through the scattered goons, and Katsuki played in this abandoned hideout as a child so he knows his way around it.
Ideal things happening during all of this:
Aizawa torn between being overjoyed that Katsuki saved Eri and then horrified/so done with this child as he walks Eri and Satsuki through how to use knives and grenades.
Katsuki being confused that neither Eri nor Satsuki know how to use a knife.
“Okay, did I have a weird childhood or did you two have a weird childhood. I can’t tell.”
Katsuki gives both children knives, and gives Eri a second knife when she loses her first one (and by loses I mean it ends up embedded in a bad guy’s shoulder)
Izuku keeps pulling notebooks and pencils out of seemingly thin air since Katsuki is openly discussing his quirk/aspects of it with the kids as they make their way through the base and by god he needs to write it down. Overhaul keeps taking his notebooks/pencils but the moment he looks away Izuku somehow has another set.
Katsuki keeps mentioning offhandly things from his childhood and the more things he mentions the more all the other heroes are like “????????”
Finally, Overhaul realizes there’s no chance of his guys taking down Katsuki as Katsuki finishes off the last or second to last one, and so he unleashes The Robot.
By this point, Katsuki already called for backup, but it’s at least half and hour out. He sees the robot and he’s like “Ah fuck.”. Eri and Satsuki already told him a little bit about it and particularly that it’s built to withstand anything short of a nuclear weapon. Not to mention it’s decently fast/agile.
And then when Eri is hurriedly relaying all this to Katsuki, she mentions that Overhaul built it himself.
Katsuki: “Wait like, he actually designed and built it. Overhaul’s the guy with the weird purity/evolution obsession right? He made this? Not somebody smarter?”
She confirms and Katsuki is suddenly No Longer Worried: “Okay, you two chill here, I got this.”
So then he goes to fight the weird beast robot, and nobody’s really sure what he’s planning. As he starts fighting it, he seems to be blasting it’s head into stuff a lot/slamming it around, but that’s not doing any actual damage, right?
See, Overhaul’s somewhat of a moron who put all of the robot’s processing/”brain” into the head area, because that’s how things are supposed to be in his mind. Katsuki figured the guy would probably pull something like this, and so he gives the robot a bunch of repeated strikes to the head area/knocking it around. Because even if the outside is super tough, that kinetic energy still travels through and can do damage to delicate circuit boards.
In layman’s terms, he gives the robot a series of minor concussions until it adds up.
The robot starts to malfunction, going somewhat rouge/pausing/getting stuck places/etc. But it’s still not destroyed and the heroes aren’t sure what Katsuki’s planning next. Katsuki is quite sure of what he’s planning next though. He lures the robot outside and then traps it in place with some large rocks or some rope or something. It’s not going to hold it for very long, but it’s enough to keep the weakened robot in place.
Then he takes aim with one arm as if he was doing an AP shot.
Everyone (heroes and Overhaul included) are kinda like ‘okay what the heck’ because even Katsuki’s strong blasts aren’t enough to really damage the robot’s exterior. Why would trapping it change that?
Then blue starts to spread up Katsuki’s arm along his veins, his hand starts to crackle and there’s 1-2 seconds of “wait WHAT” before Katsuki unleashes a blast on par with that of a small nuclear weapon. The explosion is bright blue, narrowed down to a fine point like Katsuki’s regular AP spot, but once it hits it’s target, it explodes outwards disintegrating the robot and taking out a good chunk of the surrounding land. The whole hideout is shaken to it’s foundation. Windows shatter, some cameras crack, and when the dust clears, Katsuki’s standing tall.
His left arm is still covered by that spiderweb blue though, and it’s hanging limply at his side.
Okay, so this is 90% me making up science but shhhh
So as the heroes quickly learn as an exhausted/barely on his feet Katsuki stumbles back to the kids who of course have questions, this is apparently something Katsuki has been able to do since he was 6.
He calls it “Blue Core”, and it makes his explosions super powerful by pulling nitrogen from the rest of his arm/blood stream/flesh and stocking it all up.
However, he basically never uses it because it comes at a really high cost, namely it takes several seconds of charging, does a ton of collateral damage, and by using it it takes whichever arm he used out of commission for at least the next 24 hours. He can still use his quirk a little with the other one, but it’s heavily weakened.
Obviously he can’t use this in training either, so he never thought to mention it to his teachers.
The heroes + Overhaul just watch stunned for like a solid minute as he starts making his way towards where the heroes are being held hostage with the kids because what the fuck.
Finally though, Overhaul snaps out of it and goes to fight the weakened Katsuki. The kids hide when Overhaul comes out and he throws Katsuki against a wall or something b/c he’s heavily weakened and can’t really fight with his quirk anymore, and then he struts over to him monolouging and ready to claim victory as Katsuki is laying there, slumped over and barely breathing.
And then the moment Overhaul gets close to him, Katsuki is up in a flash and the heroes can hardly even see what happened, but the next thing they know Overhaul is on the ground screaming bloody murder clutching his eyes and Katsuki is holding a blood stained knife. Then he gives Overhaul a curb stomp and he is OUT.
It should be noted, this is not any of the knives that he gave to Eri/Satsuki.
Someone, maybe Aizawa: “How many knives does he have???? I thought he was hiking????”
Shouto: “Oh yeah, at one point during the remedial courses we were babysitting kids together and he mentioned to me that he had 7 knives that day, and I honestly couldn’t tell if he brought more or less knives than he normally carried because of the children. Still not sure actually.”
Izuku: “I know he usually carried around 4 knives when we were kids but part of that was he had limited areas to hide them back then.”
Fatgum and Tamaki are both completely baffled and trying to fit this guy they’ve just been watching with the person that Kirishima described Katsuki to them as.
Anyways, so then Eri & Satsuki get the keys and go to free the heroes which are fairly close by while Katsuki guards Overhaul to prevent him from pulling a ‘gotcha’ on them. And also because the heroes are up a flight of stairs and Katsuki physically cannot walk up them right now.
It’s very emotional as Eri rushes to Aizawa and Satsuki rushes to her big sister who is now crying. And then the group heres a noise and all eyes go back up to the camera screens which are still somewhat up and running, currently focused on where Katsuki and Overhaul’s battle went down.
Turns out, before this whole mess started, the LOV sent Dabi to go take care of Overhaul because He Cannot Be Allowed To Have Arms, Goddamnit We Were Making A Point With That.
But then Katsuki went ahead and did Dabi’s job for him, so Dabi radioed back to Tomura and Tomura changed his objective to “You know, while you’re there anyways and he’s weak, might as well grab the kid.”
There’s two endings to this:
The door to the room Katsuki is in swings open and fucking Dabi waltzes in probably saying something like
“So, is this a bad time?”
Katsuki turns to look at him and in the most done, tired, angry, voice: “You asshole.”
After drugging Katsuki somehow (because unlike Overhaul, Dabi is not stupid and isn’t getting with 10 feet of Katsuki without being damn sure he’s down for the count), Dabi kidnaps Katsuki for the second time and the two of them are teleported out of the area about 10 seconds before Aizawa/the other heroes are freed just barely too late to do anything about it.
This ending would mostly be because I’d want Dabi and Katsuki to have back and forth banter of Katsuki being so 110% done with everything and Dabi being like:
“Yeah, I’ll admit, this is kinda a dick move and the universe definitely has it out for you today.”
“You don’t get to say ‘the universe has it out for me’ when you’re the one kidnapping me asshole”
And also because it sets up some serious hurt/comfort.
Katsuki stumbles his way over to a doorway on the other side of the room to go grab some rope so he can tie Overhaul up. He opens the door, and Dabi’s just standing there, having been about to open the door so he could capture Katsuki.
They just stare at each other wide eyed for several long seconds before
And Katsuki slam’s the door shut.
He takes five seconds to just stare at the door being pissed and then is like “No, fuck this, I have dealt with enough today.” Then he proceeds to barricade the door as he goes through various forms of the words ‘No, nope, fuck that, not happening’, still exhausted and beaten up and done but 100% N O T H A V I N G T H I S.
The heroes get down there to help and and they search for Dabi only to discover on the camera footage that after Katsuki slammed the door on him, he apparently thought it was so funny that he just kinda shrugged, turned around and actually fucking left. Because, you know, his main objective was already completed, and he didn’t really feel like going the extra mile today.
All of this is on camera too, so it quickly spreads as a meme, along with other choice moments from the whole hideout fight including several ‘vibe checks’, one of Satsuki throwing a grenade into the face of on of the goons that was harassing her before, and also ‘knife check’ becoming a thing.
