Martial Peak - Rise Of The Human Emperor - Chapter 10 – Treasurer Meng

An average man is reincarnated in the world of DxD! How do you survive in a world of battle-hungry monsters? With a cheat skill, of course! Devour the competition, becoming stronger with every fight! From the depths of the Familiar Forest, the Beast King will rise. (Harem, Gamer!SI)

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

Exile Ren?

The start is hell mode?

Fortunately, there are crossing benefits, and it is still a stitched monster sandbox game system!

Liver Emperor Ren? Hamster Ryan? Isn’t this basic operation?

- Description from novelbuddy

A one-of-the-kind advanced game? Liberty Online.

Dungeon master class that needed to protect his dungeon core?

No system in place to revive monsters by magic, it's up to him to keep them alive.

Unfortunately, that's not all he has to worry about.

The whole population of immortal players has set their sights on his precious dungeon? And

Woah Dungeon got conquered in the game. Many celebrated, but he cries blood tears for his mistake.

Not able to handle the pressure, he died in remorse for how stupid he was his whole life.

But then something miraculous happens. He got reincarnated back in time - one year after the game’s release!

Armed with knowledge from his previous life, He will use this chance to achieve his every dream.

He strives to reach a height where no one dares to touch or even think about touching him.

This is the story of Roan - a man who will use all his power and strength to become king of Liberty Online!