Spoiler
In the conversation between Kellhus and Moenghus at the end of TTT Kellhus has understood that the Psuke is based on passion. That means that Moenghus is weak and he states this himself, the only time he surpasses the others are in the more sublte speels like the Cant of Calling he used to summon Kellhus. The reason for his predominance in the Cishaurim is like Cause says, you're a priest first sorceror second which means your rank is not determined by your sorcerous abilities. Which means that Moenghus like Kellhus has manipulated himself into a position of great power.