I'm Not the Mastermind - Chapter 22

“Do you think sleeping with you once isn't enough after what you did to make me famous? Would you do it a second time?”Li Qingshen remained silent.Ling Momo pouted before biting her finger. “Ten times?” She asked.Li Qingshen still remained silent.Ling Momo tugged at her own hair. She clenched her jaw. “Twenty times?”Li Qingshen turned around to leave.Ling Momo was frantic. She stomped her feet. “Is twenty times still too little? You can't possibly want a hundred times.”Li Qingshen smiled. “That'll do...”

Lee Jin Woo once lived a dismal life.
He lived pitifully on a day to day basis in his five-pyeon studio filled with mold.

Then, one day, he died in a sudden fire.

When he wakes up, he finds himself inside a novel.
But there’s just one issue…
He had become the novel’s villain!

Having being plagued by same dream for the past six years, Chu Yanshen discovered a little boy who looked just like him out of the blue. It was only then did he, Chu Yanshen, learn that he had been deceived by the little lass six years ago…

- Description from Novelupdates

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