Who is the antagonist in The Kite Runner by Khaled Hosseini?

Assef is the antagonist in the novel. Assef is the local bully and tormenter in the village. He is the person who rapes Hassan: an event that will plague Amir for the rest of his life. Assef is a socio-path. He is impressed by Hitler. Although Hitler was unable to eradicate the Jews, Assef thinks he can eradicate Hazaras.