DxD: Matsuda? - Chapter 81: My First Love Benemue?

“How long has it been?”10,000,000 Years, a period of time which he dwelled in the endless abyss as a captive of war.After his fall, he lost everything to the hands of those who stand above the heavens.The twelve gods of the constellations, the Primal Zodiacs!Creatures who descended down from the absolute light to consume all.He fought against them only to fall prey to their destruction, locked away in the endless Abyss.Astroth Vermont lost it all, his will, his empire, his powers and his mind, all he knew was despair.But that’s until he woke up, Returning back to the world as someone else.The Blackest Evil was reincarnated as the Tenth Young Master of the Reinhart Family.His return is going to shape the world, returning all into chaos!Will he exact his revenge?Who knows, welcome to the land of carnage

A 29 year old civil employment exam student wakes up in a blank white room and meets a baby angel. This baby angel informs him that he died in his sleep due to heart disease like his father and grandfather. Remembering his mom and their last conversation he says that he will take on a series of life and death tests that the baby angel offers him. From this point on he must put his life on the line and fight in the stage called ‘Arena’. And Every time he clears a test he will gain abilities and weapons to increase his strength. All to clear the tests and get his life back. This is his story of his fights in the ‘Arena’.

Tianshu Fengshen list, Di Shu Shan Hai Jing, human book life and death book!
Above nine days, it is for the fairy palace!

- Description from ptwxz (translated)

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