In short, AFO was trying to kidnap Izuku and make a murderous killing machine but Shigaraki accidentally kidnapped the wrong person, Katsuki, AFO couldn't make his murderous killing machine due to Katsuki's body type, So he made himself a plaything. A doll. A toy only to fuck with (literally) After that, AFO was captured and interrogated... Soon after-.. Well you'll have to find out pookie 🌚