He punched Mankar Camoran when he was essential, being dragged into Paradise with him. They've been locked in an epic battle ever since. The Mankar Camoran you fought was a mere conjuration of the real one (I always thought he was waaay too easy.). Although, their 'epic' battle isn't so epic, they can get in about one hit each before going unconscious for another half-hour.
M'aiq has to return! And when he does, he should wield the only spear in the game, but it's impossible to take cause it doesn't show up in his inventory.