Thelus

 said he worked for all life. He was only concerned with the Eighth Doctor's well being, when he heard high pitched sounds and Lucie Miller's voice. He was part of a retro-engineering attempt to create Kaleds from Daleks, after a 'great war' that wiped out most of the Daleks and the Time Lords. This was in the Doctor's mind. (AUDIO: Tangled Web)