I play my own vampires somewhat similarly to how they're portrayed in Andrzej Sapkowski's stories (the ones in which Geralt of Rivia became famous). In my backstory there was no "conjunction of the spheres" to explain how vampires came to exist as an entirely different species alongside humans (and other races/species), but I've left myself some open-ended references to some sort of arrival in the far, far distant past.
In my version of their history vampires were probably originally extraterrestrials, but not of the Sixam sort, and I've deliberately left that part of their history vague in case I want to expand upon it at some later time. I don't have as many vampire types as Sapkowski's stories do (which are a wide variety between the grotesque and monstrous lower forms and the beautiful and brilliant highest form), but I do have a couple of varieties that are often indistinguishable between each other in terms of appearance. There are the Progenitors (the originals and descendants of the original bloodlines) and the Offspring, who are created by something more akin to genetic manipulation/mutation than magic, but of course it looks like magic in the game itself (in the form of giving and receiving plasma in order have the necessary genetic material). The way it looks is only ceremonial in my universe. ;) Vlad himself isn't considered a progenitor in my universe, but rather one of the earlier Offspring.
Similarly to the vampires created by Mr. Sapkowski, my vampires aren't really afraid of or damaged by sunlight, but most prefer to keep mostly to themselves (they consider other species generally less worthy than themselves, but they reserve outright hatred for directly perceived insults or injury), so many of them don't go about during the day. They don't consume plasma for sustenance as often as the game wants them to, because they consider it a delicacy, something to be more rare and treasured than many vampire tales tend to depict vampire hunger/thirst. In terms of gamplay, I have to "play pretend" a good bit with all that, but I've found it mostly easy to ignore the game's way of doing things. And when my vampires eventually gain the perks that let them truly be the plasma connoisseurs most of them strive to someday become, it becomes even easier to mingle with other species whenever they want such amusements.
That's not to say there aren't some that deviate from the ultimate goal of becoming the pinnacle of their cultural ideals. There certainly are. Some purposely play up the "rumor mill" version of vampires that were made up over the span of time since they first arrived. For some, that's their game. :lol: