Regarding the Cthulhu Mythos in Black Sun, here are a few of my thoughts on the matter. Black Sun isn’t intended to be a wholehearted adherent to, say, the Call of Cthulhu game universe. Instead, we are treating the Mythos as a starting point or touchstone for the Black Sun Universe in order to get folks thinking in the right direction pertaining to the concept. As such, we are adding our own elements, drawing on occult lore, grind-house cinema and cold war era gonzo culture. The Mythos makes a good starting point because most are familiar with its common tropes. We will have Deep Ones (Adaro), Ghouls and Shoggoths because, frankly, they will be popular. But, like any good weird fiction author of the Lovecraft Circle, we intend to introduce our own ideas as well. Hence the Fury Bugs and The Golem. Just sticking to the established canon would be, in my view, the same as those authors who slavishly tried to imitate Lovecraft and really just generated piles of pastiches.
I'm happy to keep this discussion going though.