Infernal Ascendancy - Chapter 28: Burn Bright in Hell

Mo Poor never thought that he would suddenly have supernatural abilities until he shot an arrow towards the sun. The absolute hit means that he can be the god on the pitch, the god of the basketball world, the big Luo Jinxian in the game… He can easily become a winner in life, spend his life magnificently, and wealth and power will not be difficult . Just as he was using this to change his destiny and enjoy his life, he met the inmates who claimed to be from the Blue and White Society… When he understood this organization that executes necessary evils in the dark of the world and maintains human security, he found his true identity Goal: I want to become the president of Lanbai. The contents of this book, D-class personnel nouns and inspirations are derived from works on wikidot. And released according to CCBY-SA3.0.

- Description from novelbuddy

After dying in an oddly anticlimactic vending machine accident, Kazuki Ren is reincarnated in the demon realm—not as a hero, not as a villain, but as the only human male student enrolled at the mysterious Academy of Ruin, a school where all the professors are demon lords and all the students are powerful, beautiful she-demons.Ren is told he has one task: survive.But there’s a catch. The Academy’s darkest secret is about to awaken, and Ren holds a hidden power that could either destroy the demon world... or rule it.Now surrounded by seductive demons with hidden motives, eldritch tomes, forbidden dungeons, and twisted exams, Ren must master his ability—or be consumed.Magic, mystery, danger, and temptation await in this dark academia harem fantasy.

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.