I Love Destroying Worlds' Plot - Chapter 1053: 16.99 First Red Star - Illusionary Forest (VI) [M]

Protect humanity from anomalies.

Chen Rui, an otaku from earth, is reborn into a human body in another world, who falls into the legendary evil, brutal world of the devil called Mozu where humans are treated as food. He has to survive while facing horrors of the devil, violent dragons and a variety of power enemies depending on a strange super system chip and his wits. Surrounded by Devil’s beauties such as black-bellied lolita princess, cold queens, violent dragons, charming poisonous devils …

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- 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.