Jyggalag is the Daedric Prince of perfect order.  Jyggalag despises all the other Daedric princes, seeing them as chaotic beings, and he constantly tries to conquer their realms and spread his influence of perfect order.  Once Jyggalag’s worshipers die, they become knights/priests of order in the afterlife, beings who have their flesh replaced with gleaming crystal, and their free will replaced with the unending desire to serve Jyggalag and snuff out any form of Chaos.