I think the Divine will kill Damian in Project E as I think that is the spritual successor to Divinity 1. The Dragon Knight game, project D however hmm, I don't know. I like the idea the DK kills a Demon prehaps the storylines of the two games will converge so in Project D the divine will appear as an NPC and vice versa in Project E.
Maybe as Shadow Tiger says, the Divine can't kill his son and wusses out at the end forcing the Dragon knight to kill him instead in his own creative way...
Ygerna died (again) at the end of DKS at least in human form anyway, that caused the divine to be freed.