Steel, Guns, and the Industrial Party in Another World - Chapter 348:

In an inaccessible village, there were a few houses on the hillside.

People from far away were attracted here and the mountain road was crowded with luxury cars, because, in this town, there was a young man with incredible medical skills who could cure all kinds of illnesses!

Cho Ryu Hyang was good at math from a young age. When he enrolled into the The Theoretical Maths and Martial Arts School, the teacher, Jo Gi Chun, recognized Cho Ryu Hyang’s talent immediately and took him in.

“Why is the thing you summon always so strange, can’t it be a little more normal?”

Lu Yu looked helplessly at the guy who was waving his tentacles in front of him.

“Who made me look up to see you every day…”

- Description from novelbuddy

Beings that create and control monsters and demons, beings that build and reign over malicious labyrinths, the chosen individuals to possess an overwhelming Unique Skill… They are the Demon Lords.