Xiaoyao, a young man from the modern era, unexpectedly transmigrates to the prehistoric world, takes over the body of the Tongtian Cult Master, and activates an Invincible Sign-in System. His starter pack grants him an innate Dao embryo, a million merits of the Great Dao, and a Great Luo sword embryo. His power soars, astonishing the prehistoric world.
He signs in at Mount Kunlun, reassembles Pangu's primordial spirit, and comprehends the laws of creation. At the Heavenly Court, he signs in and subdues Di Jun and Donghuang Taiyi, obtaining an upgraded version of the Great Array of the Heavenly Stars. With the rewards from signing in, Xiaoyao takes on numerous disciples and improves their cultivation arts. The Jie Sect rapidly grows stronger, provoking Yuanshi Tianzun and escalating the conflict between the two sects.
Patriarch Hongjun pushes forward the Investiture of the Gods plan, intending to balance the powers. Xiaoyao sees the danger and, to protect the Jie Sect's disciples, pits his wits against the Chan Sect. Along the way, he uses sign-in rewards to master ancient runes and formations, weakening the Investiture of the Gods' effect on the Jie Sect and preserving its strength.
Yet the prehistoric world remains engulfed in war. Outlandish demons have long coveted it, and invade while the world is weakened by the tribulation of the Investiture of the Gods. Xiaoyao calls on all races to put aside their grudges and fight together. Leading from the front, he battles the demon leader Blood Demon to the death. At the critical moment, he draws on the power of Hongmeng obtained through sign-in, slays the Blood Demon, and drives back the demons.
After the war, with Patriarch Hongjun's approval, Xiaoyao establishes a new order for the prehistoric world. He builds an Arbitration Hall and promotes exchanges among the races, ushering in a golden age. But Xiaoyao does not stop there: he sets out on a new journey to explore higher realms of the Dao and protect the prehistoric world.
