I'm Sorry (Katsuki Bakugo x Assassin reader)

Y/n is the childhood best friend of Iszuku Midoriya and Katsuki Bakugo. Her parents were abusive, towards her and her brother. One night when she was 8, her brother helped her leave. He took her far away, away from her parents. He took her to stay with a girl. The girl trained her to become a killer. One day when she...