I came up with this idea as a way to give a sort of "wink 'n nudge" to WoD players playing the Buffy game. Basically, I came up with slightly exaggerated versions of some of the Clans in Vampire:the Masquerade.
Of course, this is still the Buffyverse, so there' many important differences. Unlike the WoD, in which these groups make up the whole of the vampire population, these are isolated groups in the minority of Buffy vamps, much like the Order of Aurelius or any other group of vampires working towards a single goal. Many of the vampires who are part of the clan in question have strange powers resembling the Disciplines, but these powers are of unknown origin and are usually possessed only by experienced or old vamps. The vamps are still Buffyverse vamps in every way (demons in human corpses, game face, vulnerable to holy objects, instant dusting by a stake, etc.)
Some are obvious, some not so much. All are written tongue-in-cheek.
The Biker Boyz - this roving gang of biker vampires emphasize the worst stereotypes of every '80's vampire rebel flick ever made. They practically make targets of themselves with their leather jackets, piercings, and multicolored array of tattoos. It is only their fierce combat prowess that has prevented them from being dusted to a number. The Boyz usually target vulnerable towns, feed at their leisure, and move for greener pastures afterwards, which has placed them in competitions with the demon bikers known as the Hellions.
The Coven of Tremere - Watcher lore suggests that these sorcerous vampires may have originated from a cabal of mortal wizards who wished for immortality. Named after their founder, some have even suggested that Tremere and his brood somehow magically "stole" the curse of vampirism, making them distrusted by most vamps. Still, this close-knit group is feared for their combination of vampiric power with magical prowess. The coven only sires those individuals with the Sorcery Quality or the potential to gain it. As such, these creatures often hire out their services to demons and other forces of evil, and the supernatural world knows that they have another source to turn to when human wizards are too sqeamish to carry out their designs.
Venture Capital Inc. - This vampire collective is one of the few with a "public face" it presents to humanity. On the outside Venture seems to be simply another investment and finance corporation. However, it's inner circle consists of a group of vampires who use their position for illicit supernatural gain. If a demon lord needs to raise money for his cult... Venture is there. If a sorceror needs to launder money connected to his white slavery and human sacrifice ring...Venture is there. In addition to great financial wealth, many of the vampires of Venture Capital are skilled in the arts of hypnosis, better to make governments and muckrakers look the other way. They have been in close contact with the law firm Wolfram & Hart for many years, although this has changed since the firm's L.A. offices have changed management...
Haquim's Blade - This organization is actually a subset of the Order of Takara, the supernatural assasin's guild. Named after the feared vampiric assasin who held contribute to the Order's founding, all Takara vampires pledge allegiance to Haqim. There they learn and emulate Haqim's power of transforming his blood into a poisonous substance capable of bringing down the strongest foes.
The Followers of Set - This is a cult of vampires based in Egypt, dedicated to Set, the Egyptian god of evil (The Council is still in debate as to whether Set may be a vampire, demon, or other entity). These vampires await the day that Set will bring Hell on Earth, and prepare for his coming by destroying his enemies through corruption and vice. In reverence towards Set's symbol of the serpent, many of these vampires have sorcerous powers related to snakes or Egyptian magic. A few are even rumored to have made themselves immune to wooden stakes through the removal of their hearts.
and, a backstory for all those prospective ensouled vampires out there...
The Brethren of Saulot - Legend tells that shortly after the first vampire was born from the fusion of human and demon, he was pursued by a mighty demon hunter known only as Saulot. As a cruel gesture, this creature murdered Saulot and proceeded to sire him. However, to his suprise, Saulot's soul was of such purity that it remained hold of his body despite the demonic spirit invading it. This left him as a vampire with all of the strengths and weaknesses inherant, but with the original human personality and conscience - a vampire with a soul. From then, it is said that he continued his cursed existence, both to fight evil and to offer succor to those vampires who wished to regain their humanity.
The Brethren are rumored to be a group of vampires who, using mysterious mystical techniques originating from Asia, have found the ability to recover their human souls. Rather than siring new vampires, they increase their numbers by seeking out rare vampires who wish to regain their visages of human conscience, and teach them the ways by which their souls can be regained. Stranger still are tales of elders of this group who have fully supressed their demon by granting it powers of healing and insight, represented by a third eye which emerges when the vampire assumes his "game face".