Assume that if you sacrifice and consume the adrenalized blood of some living thing, you feel the life force of that thing within you and it feels fantastic and you sort of become that thing. With this assumption, it's pretty easy to see where this is all coming from, you just have to allow your mind to go there. With a goat or a stag or whatever, you become that animal, hence the animal and horns fetish. If you mix male and female blood, you feel the divine feminine and masculine surging within you at the same time. Androgyny is a fetishization of this state of mind. At its most basic level, this part of their "culture" is fetishes that come out of their blood rituals.