The Human Emperor - Chapter 30: King Song’s Bestowment

Lyle Walt is a young noble boy and heir looking forward to the day he can inherit his family’s territory. Except around when he was 10 year old, his parents started neglecting him more and more in favour of his little sister, Celes.
On his fifteenth birthday, he is challenged to a duel by his sister to see who will inherit the household and horribly loses, being cast out of his family. Afterwards, he gets treated by the family groundskeepers and receives the family heirloom Gem from him that Lyle’s grandfather had entrusted to him. From there, he begins an aimless journey with his childhood friend and former fiancée, Novem, and the Gem-turned-Jewel that houses the memories, personalities, and Skills of seven of his ancestors.

Fight. Heal. Survive.The Integration didn’t just change the Earthen Union—it tore it apart. Monsters, mayhem, and madness turned civilization into a battlefield.Yet, while the world crumbled under the weight of despair, David felt something unexpected: he felt at home.Even after being forced into the [Cleric] Class, David refused to yield. He adapted, turning his unwanted gifts into tools of both healing and destruction, forging himself into a battle-hardened healer unlike any before.

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