He's really sort of the devil. He's completely emotionally detached. He has no empathy. You find that in psychopaths. It's about power with Voldemort. It's an aphrodisiac for him. Power makes him feel alive.
“After all, from the Muslim Brotherhood's inception in Egypt in 1928, it has been a revolutionary organization committed to the imposition worldwide of a totalitarian, supremacist Islamic doctrine they call shariah.”