Arden-Sul was a powerful prophet and ruler from an old time in the Shivering Isles. Not much is known about Arden Sul. Some say he was a hero, some say he is some sort of god. The Manic and Demented versions of his death have even become part of the ritual of accession for each respective duchy. The Heretics of Mania believe that Arden Sul is the real owner of the Shivering Isles and that Sheogorath is just a man who needs to be overthrown. The Zealots of Dementia believe that Sheogorath is a living god (an Aedroth bound in human form) and that Arden Sul is the aspect of Sheogorath's mortality. The beliefs of the manics and the demented contradict each other almost completely. It is left open-ended to the player who or what Arden Sul is or if he is even real.
- The Elder Scrolls IV: Shivering Isles (Mentioned only)