Council:There is a woman in Everett who is somehow able to lure vampires in and drink her blood, only to be poisoning them with it. The blood is black and the victims seem to die from it. It appears to be 100% fatal, although I suppose that might depend on how much blood is drank. She has a way of compelling them to feed from her. While it doesn't seem to work quite the same on other species, I did feel the urge protect her as well when I encountered her, so her ability to compel isn't limited to vampires.
Buffy & Angel-verse People:Isabella and I a woman around Everett who can compel a vampire to drink her blood, only for it to poison them. Her ability to compel isn't limited to vampires, but it seems to take on a different version to humans and others, more inspiring a need to protect her. The types of vampires that leave corpses can be found with black fluid coming out of the mouth, ears, and eyes. I suggest, for now, that no one try to engage her, but that especially includes Angel, Spike, and Buffy. As far as I can gather, her blood is 100% fatal to those that drink it. The vampires around her cannot seem to stop themselves from feeding from her, and she encourages it.