Hakai Me no Yuuri - Chapter 34: The Cheats Were Spread

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.

Song Yan, a senior high school student, lost his parents when he was a child. Before obtaining a mysterious and amazing ring, he has been often plunged into a vulnerable position and easily marginalized. However, his life is changed because of the cryptic ring.

- Description from Novelupdates

One day, a gallery appeared before my eyes.…And then I was able to see who wrote in the gallery.All the heroines are ‘virg*ns’.

Ethan wakes up expecting to see the walls of a hospital room—only to find a system message blinking in front of him:[Ding! You have killed a green worm][Ding! Green worm has been added to your summoning list]