Gekitotsu no Hexennacht - Volume 4, Chapter 14: You Shall Cut the Light

Tong Nian, a cosplay cover singer, falls in love at first sight with a man she spots at a Net cafe. Chasing him, she signs up for the MMO she saw him playing, albeit it’s a super high ranked account a friend acquired for her. Who could have known he was a pro gamer, moreover a legend in the gaming circle at that!

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

A mysterious and strange world, a human civilization lacking power, and a horrible and turbulent world of human life, Luo Kai survived humblely as a prisoner. Pain and suffering honed his will. War and killing promoted his growth. He suddenly looked back. Is already one of the most powerful beings in this world.

- Description from novelbuddy