Otherworld is a dimensional plane formed by Merlyn and the Vishanti that joins this younger Demesne with the ancient realms of Faerie. The two islands echoes the islands of Great Britain and Ireland, with newer Avalon adjacent to a coterminate version of ancient Tir na Nog. Otherworld is adjacent to the Fae Realms and the Astral Plane, but otherwise closed to Yggdrasil except via Tir Na Nog.
Otherworld is ruled by Morgan le Fay. The inhabitants of Otherworld are primarily the Seelie Courts of Faerie. Titania rules the Summer Court and Mab the Winter Court. The armies of Winter stand guard at the Outer Gates, ensuring that no monsters from Nullspace enters our reality.