Cyrian

Cyrian was a young man who came from the asteroid Gaveston. When his spaceship crashed and he became stranded on the planet DV Acrol 8. Pursued by Cybermen, he was rescued by the Rani who took him aboard her TARDIS to become her travelling companion. (NOTDWU: Rescue)

He assisted her in her plot to trap various incarnations of the Doctor. (NOTDWU: Dimensions in Time)