MTL - Bringing the Supermarket to the Apocalypse - Chapter 2 companion

Mortimer Zhu is an extremely unfortunate high school student who accidentally enrolls into an academy of a dubious nature, where it is the norm to jump in front of moving trains, get dismembered during orientation, and crushed by vindictive bouncing classrooms. Can he stay alive or will he die from the rigors of school? Why have evil spirits suddenly acquired a taste for his flesh?

- Description from Novelupdates

Xiao Ran transmigrated to a fantasy world. As a dungeon guard in the Celestial Dungeon, with a special floor called the Purgatory meant for powerful demons and martial arts experts, he faced a huge challenge from the start. The Eldest Princess acquired a forbidden martial arts technique and was banished to the Purgatory. However, no one was powerful enough to restrain her. All the dungeon guards were defeated. Xiao Ran stepped up and declared, “Your Highness, it’s better for you to behave yourself on my territory” and effortlessly subdued the Eldest Princess.

He progressed from imprisoning the Eldest Princess to delivering the Great Xia Kingdom from the evil clutches of various demons and evil martial arts experts.

…

Xiao Ran was the mastermind behind the scenes.

Police officer, would you believe me if I say this is an Iyashikei game?

This story follows the rise of a regular small time criminal who had the odds against him his entire life.Just when things looked like they were about to come to an end for him, he received the power to turn his life around.Ambitious, Cruel, Manipulative, Cunning and now...Powerful.Follow his story as he makes a name for himself and grows as both a being and an organization by any means necessary, the likes of which the universe has never seen.