In the fifty-eighth year of the Great Xia era, the sun and moon vanished from sight as meteorites fell from the sky, trailing flames. That same day, demons and monsters emerged to wreak havoc across the land, plunging the world into chaos.
From then on, calamity swept across the land of China, and disorder spread from one end of the realm to the other. To restore order, Great Xia established the Demon-Slaying Bureau, whose mission was to slay demons, suppress monsters, and bring peace to the realm for the sake of its people.