One thing you can bet on: when he grows up, Damien Thorn is going to spend some serious money on shrink time. "Yeah, I always get the feeling my dad never really loved me," he'll say. "He was pretty nice to me at first: we'd go for walks along the river, and he'd lavish money on huge birthday parties. But then he got really cold, and distant - almost treating me as if I wasn't really his. Oh yeah, and there was this one time when he went berserk, dragged me onto hallowed ground and tried to stab me in the heart with seven ancient daggers. I'll be honest, I harbored a lot of resentment towards him after that."

Fatherly advice: Don't destroy the world. Don't bump anyone off, even those who find out you're really the son of the Devil. And for pity's sake, hold still you little bastard, so I can stab you to death!

See also: Jack Nicholson in The Shining. Not so much of the trying to save the world, but plenty of the trying to kill his son.