SMT III: Nocturne-1
The setting of Shin Megami Tensei III: Nocturne was at first a mostly normal Tokyo; then, an ancient ritual was performed that destroyed the human world and replaced it with a temporary world populated mostly by demons. Most of the world is now a wasteland, but there are pockets of civilization. As for the demons, not all of them are bad. They think, feel, and have sentience as well as personality. Recently, with the help of Fena and Jema, two deities, Hitoshura Nago has created a Paradise for demons known as Ai. Ai consists of two worlds linked by the trunk of a World Tree. Tenkai is located in its branches for the law-aligned demons, whereas Makai is in the roots for those demons who are chaotic. More neutral demons can be found on either end, and many travel the great trunk to seek audience or favors from Fena, goddess of Tenkai, or Jema, god of Makai. These two deities are consorts, and keep the peace between the demons while also protecting their World Tree. Although humans are accepted on Ai, there is some danger for non-summoners and combatants in Makai, as chaos demons can be unpredictable.