The Elder Scrolls IV: Shivering Isles

In the Shivering Isles expansion, see a world created in Sheogorath's own image, one divided between Mania and Dementia and unlike anything you've experienced in Oblivion.

The adventure unfolds within the Shivering Isles, a strange and unpredictable realm ruled by Sheogorath, the Daedric Prince of Madness, whose domain is split between the contrasting regions of Mania and Dementia. The player arrives just as a dreaded event known as the Greymarch looms, a recurring cataclysm in which Jyggalag, the Daedric Prince of Order, sweeps across the Isles to annihilate everything Sheogorath has built. Gaining entry through the borderland known as the Fringe, the player must overcome a fearsome guardian called the Gatekeeper before being granted an audience with the mad god himself. Sheogorath, desperate to preserve his kingdom, chooses the newcomer as his champion and protégé, sending them out across the bizarre and dangerous realm on a series of quests to stop the Greymarch.