MTL - Galactic Dark Net - Chapter 211 My name is 9527.

Inside the 3000m underwater station, an international group of scientists and engineers live and research for possible settlement of entire human race. Park Mu-hyun, a reserved dentist joins the station in hopes for a quaint life in the deep sea. However, things quickly go south when the station gets attacked by a mysterious group of people.As the water starts to fill in the living quarters, Park Mu-hyun grabs his backpack and immediately runs for his life, but where to? Now, the peaceful station becomes the ultimate survival stage of cult madness and chaos.

In a world where supernatural Awakening dictates status, power, and worth, West Einstein is nobody.At eighteen, he’s a Tier 0—unawakened, invisible, and easily discarded. In a city ruled from the shadows by gangs, factions, and mafia families with supernatural bloodlines, Tier 1 awakeners are treated like future kings, while people like West exist purely as background.That truth becomes brutally clear when West’s girlfriend publicly abandons him for Caleb Rourke, a newly awakened Tier 1 backed by a street gang. Humiliated in front of the entire school, West learns a lesson the city enforces without mercy: power decides everything... love included.That same night, something awakens within him.~ The Cuckhold System ~A ruthless system that offers West a way to climb the hierarchy by doing to others what was done to him. By targeting men who believe their relationships are secure and becoming the replacement, West earns Cuck Points, a currency that allows him to grow stronger, unlock abilities, and even awaken as a Tier 1.Failure means losing the system forever.Success means power.As West navigates high school, part-time work at a café, and a city on the brink of chaos due to newly discovered supernatural ruins, he begins to see the world differently. Gangs extort openly. Police bow instead of enforce. Supernatural ruins spark violent competition. Morality bends beneath ambition.What starts as reluctant participation soon becomes strategy.---------NB: MC never gets NTRd after acquiring the system. He is the one who NTR others.

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