Maoyuu Maou Yuusha - Volume 3 Chapter 8, “This is order — The Musket.”

The worst student of Westroad Academy. The disgrace of the Blake House. A new soul enters the body of Frey Blake, who couldn’t overcome his miserable life and chose death instead. “What’s with this body? I’ll have to work on tuning it from scratch.” The Great Mage Lucas Traumen, with the body of Frey Blake, gains a chance at revenge!

This is an alternate history. Decades after the fall of the Eastern Jin Dynasty, the world is still in chaos, although there is hope for reunification.

A civil engineer reincarnated into a magical land and tragically became a Wood, Earth, and Water Sorcerer.While still questioning where his [Earth Bear Bloodline] originated, the Chosen One next door summoned a 'player'...Watching others lead extraordinary lives, Hill just wanted to hide away.