If a demon's very existence depends on it, it admittedly casts a very different light on things. Even a predator will fight to survive, independent of corruption or malice. It suggests that it really isn't a choice, but... nor is fighting a direct threat to your own life or sanity, should it approach you as a predator.

Do you feel any sympathy for them? As the unwanted and forgotten heirs of a deity who went on to better things, surely they aren't entirely undeserving of it.