Luke O’Neill in The Thorn Birds is very similar to Assef in The Kite Runner in that they both exhibit sociopathic tendencies. Luke and Assef are both bullies in their own respective ways, but Assef represents the development of violence and psychopathic behavior during adolescence.
Both Luke and Assef display a sense of entitlement, a controlling personality, and a patriarchal-authoritarian mentality. Luke makes his own wife a housemaid and ends up controlling her finances.
Likewise, Assef controls his two closest friends, or allies, and treats them like lackeys or goons. Assef also exerts control in physical and vicious ways, which is illustrated when Assef assaults and rapes Hassan in an alley.
Another similarity between Luke and Assef is that they both come from a middle-class or affluent background. They believe that their social status and wealth allow them to own and control people, which is seen through both respective novels.