Could've Been King

The Could've Been King led the Army of Meanwhiles and Neverweres during the Last Great Time War. The Tenth Doctor described this as one of the potential horrors that would be released when the Master broke the time-lock on the war, along with the Nightmare Child and the Horde of Travesties. (DW: The End of Time)

The Could've Been King could have been a paradox as he was a "could be" king and this implies he did not fully exist. His army could also be similar to him because of their name.