The Ancient Demons are a collective term for the primordial Demon Lords.

It is said that a long, long time ago, the entire cosmic starry sky, the Immortal Realm, the Demon Realm, and the Underworld were all one entity.

Later, for reasons unknown, the cosmic starry sky separated from the Immortal Realm, the Demon Realm, and the Underworld.

People referred to the beings that existed before the separation of these great realms as Ancient Immortals, Ancient Demons, and Ancient Cultivators.