Could've Been King

The Could've-Been King led the Army of Meanwhiles and Neverweres during the Last Great Time War. (TV: The End of Time) He was "uncoronated" on April 2, 19,312. (PROSE: Time Traveller's Diary)

The Tenth Doctor described this as one of the potential horrors that would be released when broke the time-lock on the war, along with the Nightmare Child and the Horde of Travesties. (TV: The End of Time)

While on the Crucible, Dalek Caan reminisced on "Could've Been Kings" (plural) tearing apart his casing (PROSE: Dalek Caan) after he broke through the time lock of the Last Great Time War to rescue Davros. (TV: Journey's End)