ChrisReaper
Demon Slayer
I really feel like this is all because you simply didn't mention that the Heralds would be DEAD characters, and would just be referenced. I still feel like if you'd included that in your first post you wouldn't have people getting on you about this. I also have one point of contention with your idea, and that's that, to me, it seems like you are excusing the actions of the real serial killers by pinning the blame on fictional monsters. I personally believe that you can't just excuse real peoples actions by claiming that a monster made them do it. It would be more interesting if you created your own characters and had THOSE characters be manipulated and controlled by the monsters, instead of what you are wanting to do. It could and would probably be seen as insensitive to many people, even those who weren't affected personally by the actions that the serial killers did.
Well again, not giving away to much of the plot. But no, I'm not excusing these characters' actions at all. Within the context of the story, these characters are not even aware that they are part of an ancient prophecy. They have been branded by an ancient evil force, but not influenced by it. They all have perfect free wills to make a choice, and they made the wrong ones. The Old Ones didn't make them do it, that decision was all them and cannot be pinned on dark cosmic deities. So no, the story doesn't absolve them of their crimes, it emphasizes the fact that even though they had free will to choose, they still decided to go on a dark path. In fact, the second set of Blood Prophets, the Harbingers, after finding out their role in the Necronomicon Prophecy, decide to actively oppose Cthulhu and his disciples, vowing to stop his return. So their is an element of redemption in the story, even though the characters realize that even saving all of mankind from annihilation will not excuse them from their past crimes. Secondly, even if I did decide to use the whole "the devil made me do it" motif, I certainly wouldn't be the first one to do so. Dexter is a prime example of this. Throughout the entirety of the show, the main character continuously blames his "Dark Passenger" an unseen, shadowy evil that Dexter claims is responsible for his homicidal urges. The character almost never takes responsibility for his own actions, even though he use his murderous impulses for good and channels his blood lust into only killing other serial killers...and again a very successful television show.