Kumo Desu ga, Nani ka? - Final Battle ⑨

The long night shrouds the world, and the dawn is late in coming.Evil descends upon the land, causing immense suffering to all creatures.He roams through the long night, wanders on the edge of the blade, and sways between the clouds and hell.Igniting the fire of the star soul.Since the night is long, then I shall be the lord of the night.

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

This was a fragmented and disorganized world, this was a place that had been forgotten.