The Vâtrans (Ap. Aûdrat Vâtra or Aûdemit Vâtra) originally had been a minor sect of Far Harad, a remnant of the religion of the older gods which still revered the sun-god Vâtra. However the small group had long been infiltrated by Sauron's Dark Worship, and slowly gained power and influence in secret. In TA 2000 however, the Vâtrans believed their time had come, and in a long prepared violent uprising took over power in Bôzisha-Mîraz. In the end Sauron now openly was revered as the Vâtra returned, and the old moon-worship of the Ladnócans was outlawed.
This had of course been just one step in Sauron's greater plan to reform his ancient empire, and his identity of "Vâtra" was just one of many guises; in Near Harad he had used the cult of Khäz-gramaze as his cover, and in the Sîrayn he eventually had used the Tayb-sect. In the end however he was not much interested in small local reverence, which he saw only as tools of current use. The dominant state-religion of his realm was the Cult of the Eye, to which all older religions had to submit, even if they had been variants of the older dark worship themselves.
The Devamra[]
The Devamra envisioned themselves as the elite of the Vâtrans that originated from Núzhay elements, and were also known as "The Sunfire Coalition". Founded in the later Third Age, they had originally believed in the harmony between Light and Shadow, but in practice became an anti-Pogánin cult, and was used by Sauron to get rid of all those who opposed him.