After the Marriage Cancellation, She Becomes a True Ancestor - Chapter 36

Fu Hongxue was a cripple, born with a lame leg and subject to epileptic seizures. He was also one of the most powerful, legendary figures of the martial arts world, with a dull black saber that was second to none. His fame made him a frequent target of challengers, but whenever his saber left its sheath, only corpses would remain in its wake. One day, however, Fu Hongxue rescued someone whom he should have killed…and in doing so, set of a chain of events and a conspiracy that would rock the world.

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

The Return of the Condor Heroes by Jin Yong was first serialized in newspapers from between 20 May 1959 and 5 July 1961.

This is the second book of the Condor Trilogy. The story has undergone two revisions. The second edition was released in May 1976 and and the third edition was published in January 2003.

“With my knowledge, give me a fulcrum on which to place it and I shall move the world!”