Just because you can kill everyone and still finish the game doesn't mean there is no story.
This. Hordes of the Underdark and Shadows of Undrentide had a good story, and you were able to kill almost everyone.
That said, it's a feature that could hinder potential good plots.
By the way, this thread's premise ^_^ Personally, I don't think it's going to be a deep connection with the myth, but maybe just a little hint to something a bit more fantasy oriented -maybe the primordial corruption that lead to the enforcement of chaos.