Mountain Villa of Ten Thousand Beasts

Tendon Changing Classic was a supreme qi cultivation technique that did not lose to Nine Yang Divine Skill. 

Nine Yang Divine Skill was something Happy practiced before, and he knew that the greatest effect for Nine Yang Divine Skill was to increase the user's qi and Comprehension, as well as increase the user's ability in mastering the essence of various martial arts. Its pure yang characteristic also prevented the user from being invaded by qi with cold properties or poisonous properties. 

But Tendon Changing Classic was different. 

It completely changed and remolded a person's bones and expanded the person's meridian system. It can increase the user's attributes, and while it helped the user create a body of steel bones and bronze skin, it can also swiftly increase the user's qi.