How Can You Prove It?

West-Hill's Divine Skill was the most sacred and highest Taoist Law of Haotian Taoism. It was even called the source of all Taoist Law.

Unlike the Divine Skill used by the deacons of the Judicial Department, this Divine Skill was not specifically a kind of magic. It was a divine weapon given to the cultivators from Haotian.

The disciples on Peach Mountain who could use the Divine Skill were not necessarily the most gifted ones, but they did need to have the purest Taoist Heart and the strongest faith in Haotian.

Ye Hongyu, the Tao Addict, could use the Divine Skill because she satisfied both requirements. Though Prince Longqing's faith in Haotian was firm enough, because of his worldly responsibilities to the royal family of the Yan Kingdom, he couldn't keep his heart clear. So even though he was gifted, he could not practice the real Divine Skill.

For some reason, Cheng Lixue could not use the Divine Skill either.