Modern young man Lin Yu is caught in an unexpected car accident and transmigrates into the cultivation world. After awakening his spiritual root, he joins the Qingyun Sect. He trains hard and makes a name for himself in the sect's minor tournament, but Zhao Tianba grows jealous and frames him. Fortunately, Elder Xuanfeng takes a liking to him and teaches him secret arts, helping his strength grow.
When a secret realm opens, Lin Yu obtains an ancient inheritance and his strength skyrockets, but this also draws the attention of the Blood Demon Hall. While out gaining experience, he befriends the easygoing rogue cultivator Chu Yichen, and together they take on an evil organization. At the Immortal Sect Ceremony, Lin Yu meets the gentle fairy Su Yao, and feelings begin to blossom between them. On the eve of their wedding, evil forces cause trouble. To protect Su Yao, Lin Yu breaks through to a new realm and drives back the enemy.
Lin Yu uncovers a plot by the evil organization to collude with various forces, and joins forces with the righteous to fight back. After a fierce battle, he leads everyone to defeat the evil alliance. But his achievements earn him the hostility of other sects, and in anger, he strikes out on his own and establishes an immortal sect. As he builds his sect, Lin Yu repeatedly leads his disciples to explore ruins and compete for resources. Along the way, the ethereal fairy offers him crucial guidance, helping him break through bottleneck after bottleneck.
Extraterrestrial demons invade, plunging the cultivation world into crisis. Lin Yu fuses the power of the laws and crushes the invading army, protecting the cultivation world. But the crises keep coming: a mysterious organization picks a fight, and Lin Yu destroys it with his invincible power. In the end, Lin Yu successfully becomes master of the Immortal Firmament, trains a new generation of cultivators, and becomes a legend celebrated throughout the cultivation world for ages to come.
