Tomodachi no Imouto ga Ore ni Dake Uzai - Volume 5, Intermission: Nama and Shikibu

I banished the protagonist.

Shit. If only I had transmigrated a short while before.

When the heavy curtains of night descended, darkness fell upon the earth. What will later be known as the dawn of the “Dark” era, humanity once again unfolded a new path of evolution. While retaining the memories of surviving ten years in the apocalyptic world, Ye Chen awakens back on the very day the disaster struck; all he can do is protect the people dear to him, and then….

With the might of an ant, set foot upon the pinnacle of this world!

The people lost in the thralls of everyday life, aimlessly struggling for survival in this world, move forward; there will surely be a path only you can open….

- 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

This novel is also known as Master Fu's Mysterious Darling Wife

She is the The Young Miss of Military family Shen, her face is peerless, her temperament is cold, and she is her family’s treasure, but isn’t accepted as one’s child by her mother;

He is The Sole Heir to the top giant Fu Family, his power is unparalleled, indifferent high-born, the captain of the mysterious military force, and the youngest commander-in-chief.

Because of her grandmother’s wishes, she married him at lightning speed. She thought that it was a marriage that she needed, but she didn’t expect to be greeted with his extreme pampering.

- Description from Novelupdates