Itai no wa Iya nanode Bōgyo-Ryoku ni Kyokufuri Shitai to Omoimasu - Chapter 16

This is a strange world where everyone can build Dream Dungeons. Qiu Ren also becomes one of the many Dream Makers. So, welcome to the dream I built.

Suddenly appearing in a different world, it looks like I got caught up in a Hero Summoning. And of course, I’m not the Hero, but it’s another guy……and while being very cautious and scared of the cliche of the cliche-like development, I was thrown into the maelstrom of war……or not.

The Demon Lord? It was defeated a thousand years ago. Hero? He’s just the main actor in a festival. Nobles? They’re kindly taking care of us. The Demon Race? They have good relationships with Humans. Wars? It’s already 800 years since the last one. Monsters? The Guild and Order of Knight are taking care of them. Return to Earth? It is eventually No-Risk.

What I’m planning after being caught up into this? I’m gonna enjoy the life in a different world as much as I want to, go on a cultural exchange and sightseeing, and after experiencing the festival that is only held once every ten years……I shall go home safely.

The other world was――at Peace.

A kind world where the three races, the Spirit World’s Magical Races, the Celestial World’s Divine Races, the Mortal World’s Human Races, they are kind neighbors to each other, with everyone living a peaceful and fulfilling life.

But although I wished to peacefully spend a year before my return, for some reason, the heavyweights of this world keeps gathering around me, and……

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

The youthful Qin Ye was born almost a century ago, but thanks to immortality granted to him by the ‘fungus of aeons’ he can pass for a high schooler.