Summoner: Monster Girl Harem! - Chapter 102 [Bonus ] 102: Goblin Meets’ Phoenix! A Terrible Pair!

Roy’s life was nothing special. The only thing commendable was the last few moments when he saved a mother and her child from a drunk driver.
…
It’s really an egg! Damn it, what kind of monster have I become? Did I fall into Hell instead of making it to Heaven??
Join Roy as he ventures through various worlds with the Custom Made Demon King System—a system that allows Roy to draw anything he can imagine and create it through exchanging souls!

She was forced by her husband and his mistress to jump into the sea and commit suicide, only to be rescued and taken care of by the jerk's uncle for seven years.

war, blood, and betrayal carved him into something else. A legend. A killer. A mercenary whose name struck fear into both criminals and so-called heroes alike.But now, the world had changed. Lines blurred between right and wrong, between justice and vengeance. Should he step into the light, wear the mask of a hero, and fight for a cause greater than himself? Or should he embrace the darkness that had always been his home, a place where morality was just another illusion?“Don’t box me in with your shallow ideas of good and evil,” he muttered, his voice calm but edged with danger. “I do what I want, when I want.”The air was thick with tension as he moved like a shadow through the dimly lit room. The writer had no time to react—one moment, he was scribbling nonsense about legends and myths; the next, a cold barrel pressed against the back of his head.The figure smirked beneath his mask, eyes gleaming with something between amusement and menace.“You wanna write fiction?” he whispered. “Then let me show you how real legends are made.”A single gunshot shattered the silence.As the writer’s body slumped over the desk, the man holstered his weapon, stepping into the faint glow of a flickering neon light.“It’s that simple,” he said, his voice unwavering. “I’m Deathstroke.”

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