Etydion homeworld

The Etydion homeworld was the home planet of the Etydions, who were once a well-known race of powerful telepaths. They would offer their services to interplanetary military forces, using their telepathic abilities to instil great fear in opposing forces, leaving them unable to fight back. Eventually, the survivors of such attacks banded together and destroyed the Etydion homeworld in revenge. As a result the Etydion race was thought to be extinct and data pertaining to their kind was no longer included in even the most detailed of alien databases, such as K9. However, one Etydion survived, making his way to Earth where he was ultimately observed to die in 2050 after aborting an attempt to revive his race at the cost of humanity. (TV: The Custodian)