The mythic-historical origins of the Followers of Set are in ancient Egypt, as they claim to be descended from the dark god Set (who is also identified with Typhon) rather than Caine, the father of all vampires. The Setites see themselves as having a divine mandate to revive their Antediluvian, Set, in order to create an era of "paradise" for vampires and they are willing to work towards this goal in any way possible without drawing attention to themselves. Due to this connection to Set, all Setites see things a little differently than other vampires. Therefore, unlike most vampires in the modern setting, the Setites are associated with neither the Camarilla nor the Sabbat. The Followers of Set are generally found near Cairo, in sub-Saharan Africa, India, and the Caribbean though they travel worldwide in their search for knowledge to help them find and revive Set.
The Setites are known as keepers of secrets, particularly those of a thaumaturgical nature. Indeed, the Followers of Set tend to know anything anyone needs to know or can find it for them - for a price. Many vampires warn each other never to trust a Setite, as Followers of Set do not follow the Path of Humanity like most other vampires. Instead they have their own Path of Enlightenment, known as the Path of Typhon, which exalts, amongst other things, the corruption of others. Many who are snared by the Followers of Set do not realize the danger until it's too late and are either forced to become followers of Set themselves or become dangerously indebted to them.
In Clanbook: Followers of Set, it is revealed that the Setites orchestrated the Inquisition and undermined the Anarch Revolt so that European vampires and humans would remain fragmented and fighting among themselves, and thus neutralized as a threat to the Followers of Set. These two conflicts were turning points in the fictional history of the World of Darkness.
In Gehenna, the final Vampire: The Masquerade sourcebook, it is revealed, that if and when Followers of Set try to perform the Great Ritual at Ombos necessary to open a gate to Duat, the Egyptian realm of dead, so that Set can incarnate himself and live again; it is predestined that Set will instead impose on all Setites a powerful compulsion to join him in the Duat by committing mass suicide. The predominant Judeo-Christian myth established for the world of Vampire made the end of the Setites not only inevitable but the ultimate example of poetic justice.
Even when compared to other vampires, the Setites are especially pained by sunlight having it deal more damage to them faster than for any other kind of vampire. According to Setite lore, Set was cast from his family to become a vampire by the sun god Ra for his hand in killing the fertility god Osiris and Ra's hate is what causes the sunlight to burn Set and all his children more than all other Kindred. The Children of Osiris are a clan of humanitarian vampires who are relentlessly opposed to the Followers of Set because of the eternal rivalry between their respective patriarchs.
Serpents of the Light. The Serpents of the Light, nicknamed the "Cobras", is an antitribu sect of Followers of Set. They began as a rogue cult of Setites who moved to Haiti to study vodou and how its mysticism could be used to its undead advantage. Because the Serpents eventually rejected Set as a false god and chose to ally themselves with the Sabbat in the 1960s, they have earned the enmity of the Followers of Set, and vice versa.
Children of Damballah. A West African offshoot of the main clan, the Damballans are centered in the area of Nigeria and Benin, with their founding temple in Oyo, the one-time capital of the old Yoruba Kingdom. They worship Damballah-Wedo, the Yoruban snake-god, and his wife Aida-Wedo, the rainbow serpent. Very few elder members remember or know of Set and their Egyptian relations. They attribute their supernatural powers to Damballah-Wedo and Aida-Wedo, and its members are promised that eventually they will become gods themselves. At one point in the early 20th century, the main clan tried to bring this bloodline back within its ranks, but the Children of Damballah refused, and they have been separated since.
Daitya. The Daitya name themselves after the Indian demons of the same name. They are one of the most prevalent and powerful groups of vampires in India, as they combine the aspects of both clan and caste. The Daitya are a form of Brahmin caste. Accordingly, they fill the role of priest-magicians that help the gods maintain cosmic and social order. Daityans worship Shiva, and they also claim leadership of all vampires who worship Shiva as well. They tend to focus more on mental and social traits, as per their status of priest-magicians.
Priory of the Black Magdalene. The Church of the Black Magdalene is a Cainite heretical cult which renamed itself the Priory of the Black Magdalene in the 17th century. The Priory claims to guard the descendants of Christ and preserve the bloodline through selective breeding. They are said to have an underground cathedral below the French city of Marseille.