The Great Merchant in the Cataclysm - Chapter 44

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.

Ye Xiao was a superior cultivator in his previous life. The three factions of the realm kill millions of people every time they attempt to seize cultivation resources. Wealthy towns turn to wastelands in just a single night. They cover up their crime with an assertion that the towns were suffering from pestilence and disasters.

They forcibly hold all the resources for cultivation, monopolize all valuable practice materials, and keep outsiders from cultivating so that only their three factions could cultivate in the realm. Ye Xiao declared war against the three factions in retaliation for their actions. He fought alone and ended up dying in vain. However, he is reborn into the mortal body of a 16-year-old boy. He will use the powers he cultivated in his last life and slaughter his way back into the Realm. The story begins!

- Description from Novelupdates

“Wang Cheng, we need to practice more!”

“No, I want to guarantee eight hours of sleep every day.”

…

“Wang Cheng, it’s almost nine o’clock, and you’re late.”

“Didn’t you go to work at nine o’clock? It’s still a minute away. Where’s the punch card machine?”

…

“Wang Cheng, what variety show do you want to be on?”

“Is there a fishing variety show?”

- Description from novelbuddy

Kay didn't have the best life. Most of it was fairly standard, but his past was marred by a tragedy that changed his entire world. Years later he had managed to mostly rebuild his life, and had started making something of himself.

And then he woke up in a different world. A world of fantasy and [Classes], a world much more dangerous than the one he'd been born in.

The new world he's been dumped into doesn't hold anyone's hand. Even with the bonuses that being an Outworlder brings won't keep him perfectly safe. One mistake could kill him in an instant.

But maybe, with a little bit of help, he could start over once more, and start to make something of himself again. And maybe, just maybe, that something he makes himself into could be amazing. And bloody.

******

As I'm leaning right now there probably will be sexual content later on, but I might change my mind later. There definitely will be death, gore, violence, and blood. Lots and lots of blood.

I changed my mind. No adult stuff in this story.