Lin Feng, a young man from the modern era, accidentally transmigrates to the primordial age described in the Classic of Mountains and Seas, when the world was still in chaos, and binds himself to the “Mythology Balance Rating System.” The System gives real-time scores based on how much Lin Feng interferes with the course of mythological history. Its missions include maintaining the balance that allows humans, gods, demons, ghosts, and spirits to coexist, resolving major calamities, and guiding the fates of key figures. High scores bring divine abilities, magical treasures, and historical clues, while low scores cause historical disorder, frequent natural disasters, and even the disappearance of some mythological figures. The System comes with an AI named “Xiaopan,” who is sharp-tongued but occasionally shows humanlike concern.