I Can See Health Bars in Real Life - Chapter 493 - 8: Spoilers Begin! (Part 3)

Vice betrayed by his friend's, used as pawn to escape the jaws of an SSS-Rank monster.Then life decides to give him a second chance but this chance is not a reward, it's punishment.He now lives the rest his days as a rodent, the only thing that drives him is vengeance at all cost he'll have it, even if he must face the whole world to have it.

“THE NEW GATE”, an online game that trapped its players and turned into a death game, was now releasing the thousands of players that had been dragged into it, thanks to the efforts of Shin, one of the most powerful players. But after having defeated the last boss and freed everyone, he was swallowed up by a strange light and found himself inside the game world 500 years in the future and unable to leave.

A mysterious natural phenomenon caused the Earth to be plunged into darkness. The world turned into an endless bloody chaos and mankind is on the brink of extinction…

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