Mankar Camoran is the secondary antagonist of The Elder Scrolls IV: Oblivion.
He is the leader of the Mythic Dawn cult devoted to Mehrunes Dagon, and the individual responsible for setting most of the game's conflict into motion by having Uriel Septim VII and his sons killed. He is supposedly the illegitimate son of the infamous "Camoran Usurper" from Valenwood, though it is implied that this may not actually be true. He has two children of his own named Ruma and Raven.
By using the "Mysterium Xarxes", a magical book supposedly written by Mehrunes Dagon, Camoran created his own Plane of Oblivion, "Paradise", for his followers. However, the name and appearance are actually misleading as the humans there are tortured and repeatedly killed by Dremora, only to come back to life continually.
Mankar Camoran is also implied to be a delusional madman altogether with no real idea of what he is talking about: he claims that Tamriel is nothing more than another Plane of Oblivion, an outlandish claim to begin with, and also when he states the names of some of the other Planes he attributes them to the wrong Daedric Princes.