Ruler of Hell

King of Hell is a title the highest-rank of hells hierarchy a demon possibly can hold.King is ruled all Hells and demons inc.White eyed,Elite ,crossroads and other.

Known Kings of Hell.
Azazel (season 1 -2 )

Lilith (season 3 -4 )

Lucifer (originaly-season 5 )

Crowley (season 6 -7 -8 )

Abaddon (season 9 )