The world is divided into the Yang Spirit Realm and the Yin Spirit Realm. The Yang Spirit Realm teems with life, while the Yin Spirit Realm is an endless expanse of monsters and darkness. As time passed, the creatures of the Yang Spirit Realm developed consciousness, but this brought struggles for survival. The resulting imbalance of spiritual energy caused cracks to appear in the barriers between realms. Monsters from the Yin Spirit Realm invaded through the cracks, devouring the creatures of the Yang Spirit Realm.
In their struggle against the monsters, humans discovered the secrets of cultivation and gradually formed their own cultivation system. Families and tribes arose, and the strongest members of each tribe were known as Great Shamans. Nine Great Shamans, each wielding their own power, used their spiritual energy and lives to mend the cracks and bring peace to humanity.
However, as cultivation grew more diverse, conflict among humans grew increasingly fierce. Dynasties fell and new states and emperors arose. The Bureau of Celestial Observation, later known as the Meteorological Monitoring Bureau, was established to keep watch over the cracks and Yin Spirit monsters.
In modern society, members of the Meteorological Monitoring Bureau live among ordinary people, revealing their powers only when ominous signs appear. Meanwhile, some powerful cultivators have sealed their consciousness and power within Gui Artifacts, waiting for new masters to claim them.