I'm Not the Heroine - Chapter 3

Emperor Ian Veroshion, the first noble mage, was betrayed and executed. Cursed to never be reborn, he awakens a century later as the illegitimate son of a disgraced ducal line, destined to be a hostage in a barbaric land. Stripped of his magic and his throne, he must navigate a world vastly different from the one he ruled, facing political machinations and a resurgent monster threat. But the embers of his past life still burn, and Ian will not surrender his legacy. He will reclaim his name, his magic, and perhaps, even his empire.

Yo, Hi! I’m Frank, I made a deal with a demon to pay me some money for receiving a guest for a few days every week.
I had no idea about what I have done.
On May 1st, Conan ‘the God of Death’ came to my house. I was forced to let him in and we get involved in a criminal case.
On May 8th, Bruce Wayne ‘Batman’ came to me. I was forced to follow him to fight crime.
On May 16th, Hannibal Lecter, The Silence of the Lambs, came to my home. I can only say that I really can’t stand my guests.

- Description from Novelupdates

The formless ancient world was infested with despicable demons. They hunted and feasted on mankind, keeping the human civilization constantly in a weak and suppressed state.

Born as the daughter of the last martial artist of this era, that is Yeon. Her father is the world’s greatest fighter and is respected by everyone. The only problem was…… “I know it’s impressive, but I don’t have to follow in his footsteps, do I?” Her stubborn father’s dream was for his daughter to also follow the path of martial arts. Naturally, Yeon’s life was filled with grueling training. Living a dull life, Yeon’s only hobby was reading romance fantasy novels before going to bed. “If only I could live as a lady once……” After making a wish, Yeon fell asleep and entered a novel as if she were dreaming. However, her enjoyment is short-lived when she realizes that it’s not a romance fantasy, but rather a martial arts novel. “It was my dream to be a possessor, but of all things, it had to be a martial arts novel, and in the body of a supporting character who dies early!” Feeling indignant and weeping, she suddenly notices her own reflection in the mirror. It was a glamorous image. ‘Hold on. Does this mean… I could become a lady?’ Moreover, in this world, there was a man who looked exactly like the male lead in her favorite romance fantasy. He was handsome and talented, but with a wretched backstory. “Things are going to be different now.” The fate of a supporting character who dies early? Forget about it. Whether they’re followers of the devil or a heretical sect, even the worst villains don’t scare her. Why? Because she is the strongest possessor in history. This is the story of Yeon’s adventures in the martial arts world, as she stumbles along in pursuit of everything she desires.