In a certain era, there were three coexisting dimensions in the universe: the three realms of humans, demons, and Dora. They don't know each other's existence, and the edge of every realm is void. The founders of the Three Realms are three great gods. In order to understand the more mysterious power in the universe, the three great gods slept in their respective spaces. They seemed to have foreseen the disaster that would happen, so they sealed their wisdom and power and predicted: When the Three Realms become hell, we will be reborn.
Finally, an ominous sign appeared.