you were a 16 year old villain.. your past wasnt.. so great... your quirk caused your body to be attracted to blood even though you didn't want it you needed it... you were rejected by society... your parents.. freinds... everyone... eventually you turned yourself in and got put in UA high-school...

Aizawa: class we will have a student joining us today...

Momo: I heard about that.. they are a villain...

Bakugo: A VILLAIN IN OUR SCHOOL!!?

Deku: maybe they changed...

Aizawa: calm down...