The Amber Sword - volume 1 - Chapter 10

All it takes is one monster for the world to go to ruins.Life as Nadine knows it goes to shit and she has to accustom herself to life underground, that is until an accident forces her out into the real world.Caine has no idea why he saved Nadine.She is everything he hates- rich, spoiled and entitled- and yet, he couldn't just let her die.Living outside is hard enough without having to save someone else and yet, he does it with Nadine.Thrust into a world that she has no idea how to navigate, Nadine is forced to rely on Caine.Her life is literally in his hands.They soon realize that maybe the monsters are the least of their worries.

While reading a book, a sparkle of light disappeared. And, as it did, a message appeared.

You are the ruler, I am a subject, you want loyalty, I’ll give you loyalty. You are the ruler, I am the subject, you want my sacrifice, I will sacrifice for you. This lifetime, we’ll only be ruler and subject…… cannot become the one who accompanies you to experience everything.

A deposed empress, a failure of a substitute. Charging into battle, he was the emperor, and she, his general. But within the intimacy of their military tent, he was her husband, and she, his wife.

But everything was star-crossed. For the one he loved the most, he would push her into hell again and again.

- Description from Novelupdates

It’s a story about a man who got transported into a novel and possessed a slum boy. He met a noble girl and served her as a butler for 13 Years. Now the girl has already fallen from her noble life and lives in an abandoned mansion with paralyzed legs. Why did she become like that? Of course because she is the villainess in the novel.