Chen Mobai really didn't know about this.

"The 'Cantong Qi' and 'Pure Yang Scroll' of the Dancing Weapon Taoist Academy were passed down by Yun Ya, one of the five ancestors of the Immortal Gate."

"It is said that before Yun Ya came to Earth, he was a supreme elder of a sect called the Dan Ding Sect. These two techniques are the fundamental inheritance of the sect. He practiced the 'Cantong Qi' and achieved Deification with it."

"But the 'Pure Yang Scroll' requires a pure Yang body, so it was difficult to pass down and remained in his hands. Only after a thousand years of cultivation in the Immortal Gate did Yuan Yang, the ancestor, manage to practice it."