One Piece Talent System - Chapter 397 *Hidden*

He approached her and announced domineeringly, “Ten million, you're mine!” Little did he know that she would smash his head and flee in panic! Five years later, for the sake of her young son, she endured humiliation and became his wife, always on guard around him, “Get out, what are you doing coming in?” His handsome face darkened, “Woman, you couldn't have forgotten that we are husband and wife, could you?”

Hu Feng, a high school student, accidentally embarked on the road of modifying the world.

Roy’s life was nothing special. The only thing commendable was the last few moments when he saved a mother and her child from a drunk driver.

It’s really an egg! Damn it, what kind of monster have I become? Did I fall into Hell instead of making it to Heaven??

Join Roy as he ventures through various worlds with the Custom Made Demon King System—a system that allows Roy to draw anything he can imagine and create it through exchanging souls!

- Description from Webnovel

In novels with a stud there is always a Senior Martial Brother like this:

In the early stages of the novel, his innate talent is high, his cultivation is good, his appearance is handsome, and he has an intelligent, cute younger Martial Sister as a fiancée.

In the middle stages of the novel, he is caught unprepared and defeated by a young disciple (the protagonist) in the sect who’s hardly remarkable at all. From then on, he falls from his godly altar and loses his brilliance. Even his young Martial Sister leaves him for someone else.

In the late stages of the novel, he continues to turn dark, going down the Demonic Path and becoming the major villainous boss. However, the protagonist still ruthlessly defeats him and his soul is eternally sealed.

Once Qin Mo opened his eyes, he discovered that he had become this Senior Martial Brother.

- Description from Novelupdates