One reason those two might be so obscure is that they’re offshoots, unfortunately, from within the broader Pagan/Occult community. O9A, IIRC, is an offshoot from the broader ‘living/real vampire’ community, vis a vis the broader Satanic community. It’s a bit complicated. Most ‘vampires’ are just normal people, but the philosophies popular with that community (Ayn Rand, Ragnar Redbeard, Machiavelli, to name a few) means it has a very hard right streak that the community at large, especially the groups pretending to be more progressive (due to personal experience, I can only say they’re pretending), hate addressing or acknowledging in anyway. There’s a reason why vampire groups are almost always all-whites.

Anyway, since you’re interested in fucked up groups, you’ll want to look up living vampires, psychic vampires, etc. because that’s a whole cesspool of ‘goodies’ to explore lol. In a manner of speaking. Hell, popular vampire author Michael W. Ford is former O9A. You can also look up Temple ov the Vampyre, The Temple of Set (Gini Graham Scott wrote a book about them, The Magicians, which is based on her time researching them from the inside. ToS HATES her book lol. I mean, they look pretty silly in it!), and on the pretend progressive end, The Kheprian Order and House Kheperu. Not a one of them escapes allegations of abuse or bigotry. Sean Wilde is a trip, and so is his bestie Father Sebastiaan. M. Belanger is no treat either (oh, all three of those used to be very close until ‘drama’). Those three also happen to claim to be ‘ethical’ vampires, so it’s an interesting study and contrast.

Pretty sure it’s literally like. 2-3 people worldwide, of whom half are usually in prison.