I think your Moonrise Nation stuff is very interesting, and I was wondering how the Tremere and Giovanni/Hecata fit into it, being that they were usurper clans from Europe.
G'aaw thank you so much!! I'm glad so many people like the Moonrise Nation!
While the Tremere and Hecata clans didn't make contact in large numbers with the North American Continent until the setter periods, the Moonrise Nation's mythos still contextualizes them retroactively in the perspectives of the indigenous. (The same does of course go for the Banu Haqim, Lasombra, and the Setites. I'm not convinced there were no Cappadocians on the continent pre-colonies tho.)
Think of it in the same way that most European Christianized Vampires have some version of the Biblical "Cain" present in their cultural context, even though Cain would have by all accounts been an ancient man from the middle east and not a European. He is translated into their cultural understanding of their condition via Catholicism (Which itself was once a minor cult in the Roman Empire) and the stories it tells.
It would have been the same with indigenous vamps incorporating foreign concepts into their own mythos to keep things making sense to them.
Additionally, Blood Sorcery and Oblivion were present already on turtle island through the development of Caitiffs, and so these two clans in particular would be defined by their relation to the tribes interpretations of these Disciplines, rather than as "indigi-fied" clan identities themselves. It's more like they were equated with indigenous analogs that already existed prior to colonialism.
[Personally I don't subscribe to the idea that Caine was the very first vampire, I like that more as a parable in-setting rather than it being the authentic truth of vampiric origins. This game wants to be very Christian, and I've put in a lot of work to build up the Moonrise lore in a way that encapsulates the vibes without overtly including the Christo-European influences.]