Gerkenshtein:
I do not believe you have not completed your quest yet.
You probably haven`t killed enough Succubus Soldiers, Succubus Warriors, Succubus Archers, and Succubus Shamans. Or maybe you are having a bit of difficulty with the Bloody Succubi.Either way, there`s still more work that needs to be done.
Oh and don`t forget, if anything strange happens, to you be sure and take note of it.