Superior Deku (Not So Superior, Really)
In this universe, Izuku before entering U.A is killed by the son of a villain who was arrested thanks to All Might, only there was a... mistake in the murder.
Izuku's killer was the son of the villain Professor Havochaos, the name of the villain son is Kagami Date who like his mother has a quirk of superior intellect but that in turn makes him weak as glass so he compensates by fighting with gadgets only that like his mother his ego is through the roof and this in a small attack of stupidity he used an experimental weapon of his mother the body switcher changing bodies with Izuku.
Now Kagami Date or rather his conscience is Izuku who died in the process of changing bodies.
The problem is that Kagami has... certain mannerisms and habits stuck in his head, like yelling when he corrects someone or calling them ""Brainless monkeys why don't you eat a damn banana instead of asking?"".
How did Kagami get to Izuku? It wasn't out of pure convenience, it was more because of what happened with the sludge villain. Kagami was trying to ""acquire allies"" that day, although spoiler alert, it went ABSOLUTELY wrong since Kagami is like his mother, even the smallest thing gives him allergies, and he had to buy disposable tissues and there he saw All Might giving the sermon to Izuku and seeing All Might in his skinny form next to Izuku surprised him, he decided to spy on them.
Why didn't Kagami tell any villain about All Might's skinny form? Kagami's ego, like his mother's, is at the same level of stupidity and be a jerk.
Although in reality, Kagami didn't kill Izuku completely, since a vestige of Izuku was created.
-You hadn't died?.
-I think so, but I'm dead and at the same time it's not like that thing with Asimov's cat.
-...
-What?.
-IT'S SCHRODINGER, FOOL. DO I HAVE TO MELT THE WORD IN YOUR BACK? MONKEY, WANT A FUCKING BANANA? EH? A BANANA?
-Izuku? Who are you talking to?
-um, with nobody, progenitor, no one, I was... I was thinking about... adopting a cat and calling it what I said.
-why the hell do you call her progenitor and not mom? You are bad at impersonating identities.
-DON'T JUDGE ME DISGUSTING MONKEY, YOU SURELY SMELL LIKE SHIT AND EAT SHIT BECAUSE YOU ARE SUCH AN IMBECILE THAT YOU MISTAKE IT WITH BANANAS.
-IZUKU, STOP TALKING LIKE BAKUGOU OR IT WILL STICK TO YOU, AND I DON'T WANT THAT TO HAPPEN.
-uuuuh yes progenitor.
Izuku slowly decides to guide Kagami on a more correct path realizing that he is not such a bad boy, in reality it is more his mother's fault that Kagami is well Kagami.
Kagami's mother professor Havochaos who has a funny German accent Kagami in izuku's body still has it so as not to scare inko is ""it's that I listened to em... a lot of German music mom"".
Professor Havochaos is a worse parent even worse than Kotaro since she killed her husband to ""try the evolution"" on the life and Death turning him into a giant monster similar to the xenomorph, in addition to the fact that she used to use Kagami as a test subject and that's why the word monkey stuck to him, and why he's addicted to correcting everyone. At first Kagami was blinded by the idea of freeing his mother, although little by little that idea went away thanks to Izuku.
After the Kamino incident, AFO revealed Kagami's identity and that Izuku was actually dead all this time.
Kagami took advantage of that and escaped and went to Tartarus to send his mother to hell, Izuku recorded it.
Kagami once broke one of Bakugou's hands because in a biology class, Bakugou said that chocolate milk came from brown cows (Yes there were a lot of insults in German that day).
Kagami would end up falling in love with Pony.
-em, why do you choose her? I mean, that girl Uraraka is far prettier.
-DON'T QUESTION MY TASTES MONKEY IT'S NOT MY FAULT THAT I LIKE DUMB BLONDES BESIDES, YOU YOU HAVE A STRANGE FETISH FOR HELPING OTHERS.
-...why the hell did you have to say it like that?.
-my mom.
-that explains too much.