SSS-Ranked Demon Hunter: The Prodigy - Chapter 49: Solstice, Part 2

A martial art expert from the Song dynasty lives like a Phoenix that can live again in another body after death. This time, he happened to take over the body of a Japanese high schooler who is also a victim of bullying and has a bit complicated family circumstances.

- Description from Novelupdates

Hiding in the Cold Palace and eventually becoming a Boss of Sorts. Li Mu was transported to a fantastical world and became a measly eunuch of the State of Xia. Despite having initially thought that his life would be a miserable one, he had unexpectedly acquired a check-in system.

Guy Larks was famous in his original world for his widespread charity work in poverty-stricken and war-torn nations.

He was especially known for his efforts in developing schools and educational facilities for children, as well as teaching and nurturing many students.

So it was devastating news to learn that he wouldn't live past his 30th year.

But he was given a second chance! A new life in another world, as a down-by-the-dumps teaching apprentice in a world of magic and wonder. He was given no cheat, just a Repository of Knowledge holding all the information he could bring with him from his previous life.

In this new world, Guy rediscovered his life's true calling! Ride along on Guy's journey as he changes the world one budding mind at a time, as the greatest teacher this world has ever seen!

“Jiang Yu transmigrates into a novel and becomes a side character in the book.