The overall power background is a combination of future technology, superpowers, magic, and spirituality. So there will be spaceships, Chinese and Western architecture, monsters, ghosts, and vampires and werewolves.
The world is divided into six major races: ghosts, humans, demons, underworld, gods, and demons, and they are ranked in no particular order.
Brain hole. Cool article. The heroine's fighting power is off the charts.