In the four thousand years of the Three Yuan Dynasties, four things were born: heaven, humans, demons, and beasts. The world is divided into heaven/man/devil.
However, the Tianjie teamed up with the human race to destroy the demons. There are no three legs, the heaven and the earth are in chaos, and it is unclear whether they are divided or united.
The devil left behind two sons, one good and one evil, good and beneficial, evil and violent.
Either evil or good, I swear to bring peace to the world...
Intention: The thoughts of good and evil arise from this.