Phaedrus
Brother Phaedrus was the leader of the Vacuum Church on Heaven. After becoming an initiate of the Church, he was a pawn of the Hoothi group mind, sacrificing members to their cause. In 2570, the Seventh Doctor ordered Brother Phaedrus to bring the Hoothi sphere to Puterspace. In doing so, the Doctor could contact Jan Rydd on board, and ordered Jan to blow up the sphere, along with three of the sphere's four Hoothi with his pyrokinesis.
The Doctor ordered Phaedrus to leave as it was over. Phaedrus sacrificed himself to feed the remaining Hoothi on Heaven, but Ace was able to speak to the mind of Julian Milton and free the human minds that were consumed by the Hoothi group mind. (PROSE: Love and War, AUDIO: Love and War)