Eternal

Not possessing the power of creative themselves, the Eternals utilized the thoughts and emotions of so-called Ephemerals for their own ends.

Characteristics
The Eternals dwelt in the domain of Eternity rather than the small one of Time. Unaffected by Time and thus unaging, as their name would suggest, the amoral Eternals made it their principal aim in life to amuse themselves, using Ephmerals as their toys. These games were started by the Guardians, who the Eternals greatly respected as leaders. (PDA: The Quantum Archangel) Though related to the Chronovores, but they looked down on them as vicious predators. (PDA: The Quantum Archangel)

Through somewhat obscure means, as punishment, the Doctor introduced brought the force of the Time Vortex itself to bring the particularly callous Lord Prospero and his circle into the domain of Time, which would indicate that under circumstances they can transition from Eternal to Ephemeral. (DWM: Uninvited Guest)

Powers
Eternals could use telepathy and create objects from the memories or Ephemerals. They could also make objects vanish. (DW: Enlightenment)

History
Until he the Doctor and probed his mind, the Eternal known as Striker said that he had never heard of the Time Lords. (DW: Enlightenment). In the course of their games, the Eternals would sometimes pose as gods and doom whole worlds in the process (DWM: Uninvited Guest), however, carnage of the Time War horrified even the aloof Eternals to the extent that they left this reality. (DWA: Doctor Who Annual 2006)