MTL - For My Sister, I Became the World Boss - Chapter 259

The notorious imperial court lackey and the meritorious military general were well-known for their mutual dislike, a pair of arch-enemies set in stone. Who could have foreseen the unexpected change in the winds of heaven: the general injured on the battlefield, both legs disabled, and even forced by the emperor to marry his nemesis.  

With one marriage edict, two people with mutual hostility are forced to marry and live under the same roof. Yet after these long days together, they come to the realization that this fellow is not truly devoid of any saving grace/unattainable and high out of reach.

- Description from Novelupdates

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

After living in a desolate land, where there wasn’t even a single blade of grass and hunger was an everyday reality, Min Sung finally returns to Earth: his home.

“For those who dare call themselves gods, I, Wen Ran, will crush their legacy beneath my feet. Even dogs are more honorable than those filthy bastards!”A feared Godslayer, who, due to betrayal, perished under the might of the heavens, having his world destroyed. Saved by a mysterious system, Wen Ran was granted a second chance at life but reincarnated in the body of a lowly slave. Hunted by the gods who sought his head, Wen Ran vowed to reclaim his title by showing heaven his vengeance as a 'God Slayer.'