At the beginning of the ancient times, there were ten major races in the world: Demons, Celestials, Spirits, and Humans. Due to inertia, the Celestials and Demons had been at odds with each other for generations, and the two races were incompatible. Thousands of years ago, there was another war between the two demon clans. Both sides suffered heavy losses, so the two clans made a truce for a thousand years. Nine hundred years later...