Jaywalker_Holmes

Ren, a modern doctor and a secret master magician, suddenly finds himself inside a random book he picked up at the airport...as the villainous older brother of the protagonist. As the bad guy, he's supposed to make life difficult for the Male Lead until the latter grows up and kills him in revenge. However, looking at the broken teenager in front of him, Ren can't help but feel his heart soften. 
Fang was an orphan who had never known what a family is. Abandoned at birth, all he knew was pain and fear. He loved nothing, and wanted nothing...until he saw the angelic Wade. To save Wade, Fang didn't hesitate to sacrifice himself. ..after all, there was no one to cry over him.
But then, Ren appeared and turned his world upside down.

The Villain Saves the Male Lead

Professor Luke nodded. "Nephew Fang is right. If I was in his place, I wouldn't trust me, either. So, Chairman Ren, please cast fidelity magic on me," he said seriously. "I almost harmed the sacred bloodline of the original royal family of the Valley Kingdom with my own hands, stupidly thinking I was protecting Fang. I don't want to take that chance again, ever. I promised my big sister – Fang's mother – that I would develop the Valley Kingdom, and I promised to myself that I would protect my big sister's descendants, if there were any. If I can't even do these two things, then I don't deserve to live."

Ren fixed his golden eyes on the man in front of them, thinking he was a bit of an extremist.

"Are you not willing to give me this chance to atone for my sins?" Professor Luke asked Ren.

258 – Fidelity Magic