The Dark Utopia
The dark utopia is a gloomy dimension that lies beyond the usual universes. A kind of extra-dimensional dungeon, in which the worst beings of different universes were banished, corrupt gods and cosmic horrors can be found here as well as the long-forgotten mistakes of earlier gods and terrible experiments of long-lost civilizations. Even whole peoples of bizarre beings were banished here to forget them. Although most of these beings were sent here to die, the dark utopia is infested with life.
Over the millennias, some of these beings changed and adapted to their new surroundings. Some became the aggressive flora and fauna of the Dark Utopia. Most of the more "sociable and civilized" of these beings were forced to work together for reasons of necessity and in order to survive. Over time, after mutual distrust and cultural / language barriers were more or less removed, the beings built large, protected cities and formed their own bizarre and strange cultures. Cities grew into metropolises, smaller realms developed into empires and beings began to regard this dimension as their new home.