Story of The Ancient Demon King! - Chapter 64

High school student Mikoshiba Ryouma was summoned to a different world in the middle of a war. Sensing the malice from the one who summoned him (a summoner of the O’ltormea empire), he uses his martial arts to run away, killing important people of the empire during his escape. After the escape, he rescues two twin sisters from the hands of thieves. The sisters who can use magic, swear to serve him as subordinates. Thus, Ryouma begins his journey on the path of the supreme ruler.

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

In the residence of the Duke of Zhenguo, the legitimate young miss, known for her icy demeanor, had transformed overnight.She, who usually regarded no one, woke up to confront anyone she saw with a few harsh words, using her frail body to intimidate so much that no one dared to touch her.Afterwards, this legitimate young miss began taking on retainers, nurturing powerful officials, engaging in commerce, and recruiting troops… Every act so shocking and audacious, it defied the norms and provoked fear in all who spoke of her!Yan Wanqing was seen as an enchantress and a disaster by the people, a thorn in the flesh and a nail in the eye that the ministers wanted desperately removed, an entity everyone shunned as if she were a venomous snake.Only the Crown Prince Mingyue, descending from the divine altar, in the dark, godless alleys, grasped her neck and repeatedly asked her, “Will you marry me or not?”

I traverse along the pathway of darkness and imagination…