Earth’s Best Gamer - Chapter 12: Ren Hamlet. Ninth Uncle?

Silas Greenfield, a master assassin, dies in a bloody betrayal — only to wake up in the body of a random extra in a fantasy world straight out of a game he used to play. But Silas isn’t here to follow some prewritten plot. With his deadly skills and sharp mind, he’s determined to rewrite the rules and carve his own path.In a kingdom full of power struggles, royal intrigue, and dangerous secrets, Silas must navigate a world where everyone has their role — and he’s ready to break them all.Can a former assassin outwit fate and rise to power, or will he become just another pawn in a game he refuses to play?

Apollo Kaiser, a boy who bore the unlucky fate of being unable to grow strong, was condemned by his family.

Discarded by his mother and abused by others, Apollo gives in to his rage.

However, this action results in his death. Many would believe it to be the end, but Apollo's death was a required catalyst.

The Demon Monarch System finds its heir and attaches to his soul, bringing him to a new world where he starts his journey to supremacy.

This difficult journey rife with conflict, conquest, and brutality shall serve as Apollo's temperance.

Watch as the heir of the Demon Monarch rises above all, conquers Sin, subjugates unthinkable enemies, and even brings about the destruction of worlds!

The rise of the next Demon Monarch begins...

[ Detected: Player Raizel has been given the choice to acquire a Forbidden Class ][ Do you wish to accept it? Yes/No? ]“Yes.”[ Congratulations! You have acquired the Forbidden Class: Anti-Magus ]__“Throughout Heaven and Earth, Mages are everywhere. But who can stand against me?” – Raizel Ashblade.__Victor Lee, a professional treasure hunter from Earth, one day dies accidentally and finds himself in a Parallel World, where a Dimensional Game influenced every aspect of society.Now transmigrated into the body of Raizel Ashblade and equipped with the Forbidden Class: Anti-Mage, he must set forth in search of the strength and mysteries that this new World has to offer.Can an enemy of all mages survive in The Game of Supremes?

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