I Am a Rune Engraver, Carrying a Knife Makes Perfect Sense - Chapter 37 - The Three-Second Man

A girl who calls herself a demon appeared before a timid student named Fumio Kijima. The girl claims to be a campaign girl from the demon world and she gives him the ability to “summon a room” from nothing but thin air.

At first he doesn’t abuse his power and uses it as a convenient ability in his every day life. But one day he is bullied by his classmates under a false pretext and is made to suffer. In the past he would have wallowed in misery and cried himself to sleep, but now he had a power to call upon.

“I will make them regret it!”

Using his powers to summon his “room”, he begins his era of confinement and brainwashing to achieve his goals.

“Guokuo, Guoguo, ci… ciguo cake, fragrant…”

“Brother, after Qiu’er finishes eating this delicious, golden pancake fruit, can you tell Qiu’er another story?”

“Brother, Xia’er has signed up for the singing competition, will you teach Xia’er a song?”

“Brother, can you dance folk dances? Chun’er wants to learn…”

Zhuang Zhou dreamed of a butterfly, and the butterfly waved its wings gently, changing the wheel of life in suffering, and also changing the sky of Shengyu.

- Description from novelbuddy

Diablo Volfir, a mighty magician, was sealed for aeons due to the schemes of the 12 Gods, but 66666 years have passed since then, and he descends to earth once again!