The Extreme Ancient Era split apart, forming the Nine Realms, one of which was the Mysterious Demon Immortal Realm.
However, the immortals from the Daluo, Penglai, and Kunlun Immortal Realms, as well as the wizards from the Immortal Witch Realm, never considered the world of the Mysterious Demon to be part of the Immortal Realms, thus habitually referring to it as the Mysterious Demon World.
The Mysterious Demons of this realm could be traced back to the Ancient Evils of the Primordial Era.
However.
At the end of the Primordial Era, the Extreme Ancient Continent fragmented, and one of these fragments harbored the fall of one of the most powerful Ancient Evils of that time. This Ancient Evil possessed the strength of a Heavenly Sovereign and was among the top-tier even within those ranks.
The corpse of this entity began to emit a terrifying and eerie corpse mist, which enveloped the entire continent for tens of thousands of years before it dissipated.
