He nodded. "The antithesis of angels. When a human soul corrupts themselves far enough, whether that be through sin or some other circumstance, they go to Hell. In Hell, they become twisted around until they're not even human anymore. They become a demon. Demons can't have their own physical form either, so they need to borrow humans as well, but unlike angels, they don't require consent. They just borrow the body of whomever they choose without permission."