The territory closest to the Demon God Realm's defense line was governed by a ruler named Xuantan Demon King. Although Xuantan Demon King was close to Earth, he wasn't fond of blindly expanding his territory. Thus, when three demon kings from the Demon God Realm teamed up to invade Earth, he did not participate. Instead, he sent some Great Demons to support, as a gesture to save face for the other demon kings.
In fact, Xuantan Demon King's choice proved to be right. Although the three demon kings had a smooth start in their invasion of Earth and almost completely crushed the Earth Evolved Beings,
it was on a certain day when Silver Tooth Demon King fled back to the Demon God Realm in panic, Sky Moon Demon King and Golden Feather Demon King fell one after another, and the Great Demons they took suffered heavy losses, making Xuantan Demon King aware of the grave situation.
