Time-Gun of Rassilon

The Time-Gun of Rassilon was a weapon created by Rassilon shortly after the Alliance of Races' war with the Hyperion. Count D'if and Rassilon played a game of Rassilon's roulette to decide the outcome of the Alliance's war with the Cybock Imperium. D'if lost and was wiped from history.

The Time-Gun was eventually kept on the Shadow Proclamation vault-world of Janizzar. The Cybock Imperium attacked the world and stole the Time-Gun, taking it to Earth. The Twelfth Doctor encountered them there and challenged their leader to a game of Rassilon's roulette. The leader of the Imperium tricked the Doctor and turned the gun on him, but when the gun was created Rassilon programmed it not to fire on Time Lord DNA. The Gun backfired and wiped the leader of the Imperium from history instead. (COMIC: Gangland)