Katsuki Bakugo:
In this AU, he looks more like his father, even needing glasses. He was heartbroken when Izuku was announced quirkless, since they couldn't be hero partners anymore but Izuku said he would be his biggest fan instead. He refused to allow anyone to bully Izuku for being quirkless and would beat up anyone who tried, eventually they started dating in middle school. Katsuki appears to be a really calm person but that's only because he's usually with Izuku, the longer they're apart the angrier he gets, his favorite thing is sitting between his boyfriend's thighs.
Izuku Midoriya:
In this AU, his hair is a much lighter green. Since he was quirkless, he originally intended on becoming a quirk analyst, he says it's because he's interested in quirks and how they work (which is true) but the main reason is because he wanted to make Katsuki the strongest hero. He received a quirk from someone (who he now calls his mentor) at the age of 13 and was trained how to use it properly so he wouldn't hurt himself, although he only accepted the quirk if he was allowed to tell Kacchan about it. He had a hard time thinking of a hero name (since no one ever called him Deku), but eventually decided on one when he remembered Kacchan's nickname for him, Bunny (because he jumps around a lot when he's excited).