Occuli

A villain in my imagined universe, where a single Cult rules all of a Medival nation.
Occuli is the priest that heads this religion. Extremely selfish and power-hungry, he climbed up the ranks by hosting an Eldrich parasite.
This parasite is also an envoy of the "being" that his religion worships.
Just how much of his decisions are made by the parasite, nobody knows. But people would not dare question his authority or his abilities.