Creating a universe I wanted both players and a DM to feel like they could understand the structure of everything from a single illustration.
There are four layers to the structure of the universe. The realm of mortals, which is carried by the Goddess Regna. The realm of Gods and mythical creatures which is fragmented in floating islands, each inhabited by a specific group or type of creatures. The realm of the dead, located at the feet of the Goddess, where once living creatures spend an eternity as sort of stretched out frame of their last moments alive (endlessly reliving them) and the final layer is the eternal black void surrounding the previous three.
It is an isolated realm, which can be populated by as many or as little creatures as a DM wants. Making it very easy to customize the world to ones preferences.