Youkoso Jitsuryoku Shijou Shugi no Kyoushitsu e - Volume 2, Chapter 1: The abrupt beginning of turbulent times Part 4

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.

The Soaring Dragon Continent is a world of summons, you can only become strong if you become a summoner! Yue Yang, an average high school boy, was suddenly transported into this world. When he woke up, he was greeted with a lot of worried faces and found out that he had assumed another person’s identity. Turns out he’s the good-for-nothing third son of the Yue Family, who had just recently drowned himself because of a failed engagement. Unlike the third son of the Yue Family who was useless in summoning, Yue Yang succeeded in making a contract with a summoning grimoire on his first try, even when the other guy failed for the past fifteen years. Others would have a headache making contracts with beasts afterwards, but countless beasts tried to gain favour with Yue Yang instead, acting like a good kid before him.

A man was transported to Ancient China and eventually became a servant of a declining household without a male heir. He utilized his wits and modern knowledge to help the household and eventually become trapped in the sea of political turmoils of the period.

- Description from Novelupdates

I Became Hades, the God of the Underworld from Greek and Roman Mythology