The Cult of Zulkir is a religion that worships the Elder God Zulkir.
Zulkirite death cults exist across the cosmos (though they are usually forced to operate in secret), and worshipers of Zulkir often intentionally expose themselves to supernatural plagues.
Theological Differences
As with all major religions, members of Kulkirite death cults have disputes both internally and with other theologies.
Internal
Most members believe that Zulkir is not an entity in the sense of most "modern" divinities (i.e. a single intelligence) but rather an intelligent contagion seeking to spread itself and remake the universe. Some believers of this theory state that contagion with Zulkir is the next phase of life, a glorious unification of souls through the corruption of flesh.
External
The Cult of Zulkir has a significant theological difference with the smaller but quickly spreading Cult of the Unnamed. Whereas the Cult of Zulkir preaches unity in the death or undeath of Zulkir's plagues, the Cult of the Unnamed promises total oblivion, the end of all things. The next-phase theology (to which most but not all Zulkirites subscribe) is at odds with the entropic Unnamed, and the result is often violent.
Spread
Perhaps the only space in the cosmos where the Cult of Zulkir has been allowed to flourish is in the Nippon States, where it is rumored that the secretive palaces of the Daimyos hold abominations of Zulkir, among other vestiges of the Elder Gods. There is some speculation[1] that the Naga's intense hatred of the Nippon States is related to the strong presence of Zulkir worshippers there.
The Black Cell Lab revivalists within the Knights Mercantile also possess a strong Zulkirite strand.