In the past, the ancient mythical beast Qilin forged seven demon-slaying swords, including Xuanyuan and Chengying, and enlightened seven practitioners in the world to become the descendants of the Seven Swords. At the same time, a snake demon in Changshou City who had practiced for a thousand years killed living beings in order to increase his cultivation. The descendants of the Seven Swords, adhering to the duty of protecting the peace of the world, fought with the snake demon on the Black Demon Cliff and sealed it. Five hundred years later, just when the contemporary Chengying Sword Master noticed the anomaly and reinforced the seal, the snake demon took the opportunity to break the seal. The Chengying Sword Master desperately protected his mount, the donkey, and took the Chengying Sword and fled down the mountain. Luo Xiaotian, the waiter of Fengyun Tavern, once met a donkey on his way to deliver wine to a drinker in the mountain and was recognized by the Chengying Sword. Since then, he has caused a series of disasters, and finally realized the ultimate secret of the Chengying Sword through his own efforts.