Twilight of an Age
The Crusader is the armored fist of the Dark Gods. So long as followers of the gods of light stay the hell out of his way, the Crusader turns his wrath against the demons that would destroy the world his own gods want to rule. Follow the Crusader if you must win at any cost.
The Crusader’s methodology thus far has been fairly straightforward: find a hellhole, gather forces, crush the hellhole, raise a citadel on the ashes using the hellhole’s magic. When others destroy hellholes, that reduces the number of citadels that the Crusader can raise, which makes him more than a little unhappy.
When you boil it all down, the Crusader and the Hierophant are flip sides of the same coin. The Crusader does a good thing for a bad reason, and the Hierophant does bad things for a good reason. The two are almost certainly bound for a collision at some point.