Annihilator

The Annihilator was a temporal weapon designed by the Daleks to erase whole races from time during the Last Great Time War. However, it erased an entire species without affecting the timelines, meaning that the rest of the universe remembered them even though they never existed; additionally, as the War Doctor pointed out, it meant every member of the target species would feel itself being erased.

It was originally used by the Daleks to erase races such as the Vildarans. It was later used by Collis to erase the Technomancers. (AUDIO: Legion of the Lost)