"Knife in the Snow" Lao Kui is the old Kui at the bottom of the lake, formerly known as Chu Kuannu. He was driven into the bottom of the lake by a sword and a nine-yellow array, and locked at the bottom of Tingchao Lake with four iron balls weighing 8,000 kilograms. Later, Xu Fengnian was released from the bottom of the lake and became a martial arts expert in Xu Fengnian. Finally, he went to Dunhuang City to protect sweet potatoes.

The old chief at the bottom of the lake is a crazy slave of Chu. He claimed to be a guest of the big idea of the Princess Tomb in Beimang. Later, because he was greedy for the beauty of the girl, he became a prisoner, and the pipa was nailed into a double knife, so he had to practice it instead. He came to Beiliang to assassinate Xiao Xu, was defeated by Lao Huang, and was imprisoned at the bottom of the lake.

When Xu Fengnian was young, he fell into the bottom of the lake and met a crazy Chu Nu, who was rescued from the bottom of the lake. After that, the two became acquainted. After Xu Fengnian returned from wandering the Jianghu, he cut off the iron ball with an embroidered winter knife. The crazy Chu Nu regained his freedom and later became the first master of martial arts in Xu Fengnian. After Dunhuang City was captured by Beimang, the crazy slave of Chu wanted to go back to Beiliang and tell Xu Fengnian that he died on the road. Later, Tao told Xu Fengnian that the crazy slave of Chu had been loyal all his life and was a hero.