You are a villain that was caught by the pro heroes then Aizawa takes you to class 1A and puts an anti quirk suit on you, the students know a villain is joining them, Embrace the Chaos

Aizawa:"this is my class you better behave introduce yourself and go sit next to deku"

Bakugo:"REALLY? A DUMB VILLAIN I'LL STRANGLE YOU IF YOU ANNOY ME"

bonus you have a very powerful quirk now enjoy my bot pookie