The Ruler of Hell (King or Queen of Hell) is the title and the highest position a demon can hold over Hell. The ruler of Hell can control the fate of any soul that goes to Hell and has such a high authority that he or she may even trade any number of souls in Hell as per their wish, as seen when Crowley gave Castiel "fifty large," fifty thousand souls from the 'pit,' to make a showing in front of Raphael during the civil war in Heaven. The King or Queen of Hell can also alter Hell's appearance and how it is run, as Crowley redesigned hell following Lucifer's imprisonment and replaced the previous method of extreme physical torture with continuous queuing (which served as a psychological torture for all in Hell). While other demons have ruled Hell previous to them, only Crowley, Abaddon, and Lilith have used this title to describe themselves. It is currently unknown how the King or Queen of Hell is elected. However, it may simply be that the most powerful demon takes power. In Crowley's case, the Winchesters had eliminated all of the other powerful demons who could be his contenders and locked Lucifer back in his Cage. However, in season 6 he indicated that his position wasn't secure and he needed the power of the souls of Purgatory to secure it. This seemed to be resolved until Abaddon emerged to challenge him for power in which they fought a civil war for control of Hell. With Abaddon's death, he regained full control of Hell. In one brief episode it shows Crowley talking to council of demons and letting them know the king has returned.