Lucern Portillon (Varaxil)

 was the twin brother of Finicia. He said his father was Aleister Portillon, but he wasn't. He travelled back to 17th century with the Eighth Doctor and Mary Shelley to find the witch that was trapped in a well. He observed the operating procedure of the TARDIS, and piloted it to the edge of the vortex. He was in fact a Varaxyl impersonating the son of Claude Portillon, and was searching for a human that could channel Odic energy. (AUDIO: The Witch From the Well)