Tepesh

Lord Provost Tepesh was Prime Cardinal of the Arcalian Chapter of the Great Houses during the time of Rassilon. He also was secretly a Great Vampire.

Biography
During The Time of Chaos (before the Gallifreyans became Time Lords), Arcalian Provost Tepesh, Lady Ouida and Arata comprised the Committee of Three: an investigative group authorized by the Gallifreyan Inner Council to look into the work of Cardinal Rassilon. With the aid of the Great Mother of the Sisterhood of Karn and the High Priestess Cassandra, Tepesh broke into Rassilon's Foundry.

Inside, he found Rassilon, and quickly discovered evidence of the Cardinal's work to create the ability to regenerate and his efforts to lock all timelines into one cohesive Web of Time. As part of this, Rassilon had found and trapped a force he called the Divergence in a pocket universe, fearing their power to completely destroy the Web of Time. As an added measure, Rassilon had also made sure that the humanoid form was the only dominant life form in the universe via a series of biogenic mutagens scattered on tens of thousands of worlds.

Tepesh, in a fit of fury at Rassilon's ego, revealed that the Committed were in actuality Great Vampires, and that Tepesh was a direct descendant of the King Vampire. Shortly after revealing the Vault where he had imprisoned the Divergence, Rassilon activated a failsafe that firestormed the interior of the Foundry, incinerating Tepesh and the others. (BFA: Zagreus)

"Rebirth"
While dealing with the aftermath of the explosion of Anti-Time, the TARDIS created a series of holographic projections, taken partly from reality and partly from the memories of the Doctor, Charley Pollard and the TARDIS itself. One such projection it created was the event at the Foundry, looking for information on the Divergence. Inside this projection it placed Charley in the role of Rassilon and itself in the role of Tepesh's cohort Arata.

Soon after the TARDIS was drawn into a special corner of the Matrix and reduced to scrap by Rassilon and Zagreus. Before being destroyed, though, it recreated projections of Tepesh, Reverend Matthew Townsend and Uncle Winkie in the Matrix to help return fragments of the Doctor's mind to him. The projection of Tepesh had a rematch of sorts with Rassilon, but was killed with a dagger forged from the essence of the TARDIS. (BFA: Zagreus)