You can side with Mania one time, and with Dementia the next, without affecting the story line. It doesn't matter what you pick, and you don't even need to be consistent in your choices if you don't want to. At any rate, you will be asked at various points throughout the main quest line (and during several side quests) to make decisions that side with either Mania or Dementia. He's also completely and totally hilarious. Sheogorath is a Daedra Prince who is completely and totally batshit insane. Mania and Dementia are the two factions that rule the realm of The Shivering Isles, with ultimate rule being held by Lord Sheogorath. Each quest will earn you an achievement once completed, so make a back-up save before starting either of these quests. *You can choose either of these quests to continue. Ritual of Accession (Ritual of Mania/Ritual of Dementia) * If you want to find a specific quest in this page, use the CTRL+F search function of your browser to type in the name of the quest preceeded by a ' # ' marker (like ' # Through the Fringe of Madness'). The rest of the achievements after these two are not subject to your choices, and therefore are not missable. To avoid a second playthrough, make sure to create a back-up save before making your choice, so you can complete one quest first to get one achievement, and then reload the previous save to complete the other quest too and get the other achievement as well. Therefore the two achievements related to those quests ('Ritual of Mania' and 'Ritual of Dementia') are missable: Duke Mania, Shivering Isles and Duke Dementia, Shivering Isles. The choice you make will determine which quest will trigger afterwards, and an achievement will be unlocked for completing each of them. This choice is the only one in the entire game which has an impact on the achievements. You can swim out to the island containing the door, or ride your horse and let the horse do the swimming.ДЄlthough there are many, many side quest available in the Shivering Isles, in this walkthrough we will focus on the main storyline quests only, leaving it to you to seek out and complete the optional ones.Дuring the course of the main quest (during the 'Ritual of Accession') you'll have to make a choice. For a map reference of where to locate the door, look in the water of the Niben Bay down in the South of Cyrodiil, directly East of the city of Leyawiin. You can now access the DLC through this door. After 24 hours of in-game time (sometimes it may take up to 72 in-game hours you can use the 'Wait' command if you want) you will get a pop-up telling you that 'A strange door has appeared in Niben Bay.', etc., etc.

The shivering isles