Demons are cultivated by gathering the spiritual energy of heaven and earth, and contain essence in their bodies. Human beings can obtain it, which can help with cultivation and serve as a medicine guide. If the demon can be resurrected, it can be ordered to work for oneself. For thousands of years, the human race has been killing the demon race for its own selfish purposes. The two races have been grudges for a long time, and finally a war broke out. The war lasted for a hundred years. The outbreak of the war made the humans realize the problem, and they negotiated a symbiosis contract with the demon clan. Since then, the war has ended, and the human and demon clans have ushered in a new era of peaceful coexistence.
Purpose: Probably all living beings are equal and maintain world peace.