Larivan

 was a slave of the Infinite warrior. The Eminence wanted him to take the Breath of forever and become part of the Infinite. He met the Fourth Doctor and Leela during his transformation. He wanted the Doctor to warn his family. He noticed Sarla and Tillegat in the construction workers. The Doctor tried to get rid of the Eminence conditioning on him. (AUDIO: Destroy the Infinite)