Approximately the state religion of the Necrarchy, the Mortuary Cult stewards the souls - as distinct from the spirits - of the quiet dead, those who would not respond to a resurrection if it came knocking. They are noted for being able to wield the talents of the dead - those things that were most intrinsic to them in life.

(Fun Fact: The Necrarchy's monarchy is itself inherited through the Reliquary of Noble Souls.)