When Ling Mo transmigrates into the body of Ling Yue, the third princess of the Azure Dragon Kingdom, the original owner has already been locked in an iron cage in the palace's rear courtyard for twelve years. At birth, the original owner awakened a low-grade mortal beast phantom in the shape of a black snake and was branded a disgrace to the royal family. Her mother, Empress Su Wan, was falsely accused of “having an affair and tainting the royal bloodline” and ultimately forced to drink poison. The original owner, meanwhile, was locked in the cage by the empress, mother of the second princess, supposedly “to keep the little princess amused.” Every day, she was whipped, fed rotten food, and made to feed her blood to the little princess's spirit-beast phantom. The little princess, Ling Yao, also tormented her by using her as a “living target” for throwing stones. Just as she was about to die, Ling Mo took over her body. At first, Ling Mo relies on knowledge and fighting skills from her previous life to protect herself inside the cage, secretly observing and learning how people cultivate on the Divine Boat Continent. After awakening the black snake phantom's special ability to devour the energy of other spirit-beast phantoms and evolve, she gradually breaks free of her restraints and embarks on a path of revenge. In the middle of the story, she rises amid the conflict between the four kingdoms, exposing the dark secrets of their royal families and breaking the monopoly of the belief that “divine beast phantoms reign supreme.” In the later stages, she breaks through to the Heaven-Commanding Realm, slays every enemy, ascends to the divine realm, and reshapes the laws of the Heavenly Dao on the Divine Boat Continent.