The Wrong Way to Use Healing Magic - Chapter 23Vol 16.

The amiable looking patriarch is gazing at a stone monkey: “Wukong, what do you want to learn from me?” “It’s all up to master’s instruction.” The stone monkey respectfully replied: “As long as I will be able to beat up Tathagata, then it’s alright.” One hundred years later, the stone monkey defeated Tathagata and ascended the throne, becoming the Jade Emperor.

- Description from rhadoko

Gu Shanhai witnessed this great world of numerous heavens and discarded his third life.The gods of the human realm forged an eternal utopia with blood and fire.The King of the Red Dragon led his knights, patrolling the never-setting empire.The scholar, with a smile and a sword stroke, depicted thousands of miles of rivers and mountains, while monsters opened their eyes and stretched forth claws, giving birth to all manners of demons....'Everyone here is a player; you can't call me abnormal just because I haven't been digitized, right?'

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.

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- Description from Novelupdates