Demon King of the Royal Class - Chapter 248

When he woke up, Rono traveled to the world of pirates.

I thought I could live happily and peacefully.

But the appearance of Tianlong people broke this situation!

Rono, watching his parents being shot to death by Tianlong people!

Under extreme anger, Rono awakened the system and vowed to kill all the Tianlong people!

From then on, a [Extremely Evil One] who specialized in hunting Tianlong people was born!

Wherever Rono went, the Tianlong people shivered!

Admiral?

Two more and I will kill all of you rubbish!

Karp: The Evil One?

He is a monster created by the Tianlong people, and one day the Tianlong people will pay for it!

Roger: 【One Piece】?

Compared with [The Evil One], it’s nothing but a cloud!

Whitebeard: [The strongest man in the world]?

No, no, Rono is the strongest!

Rocks: In terms of killing Tianlong people, Rono is the first, I am second, everyone else is garbage!

- Description from novelbuddy

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.

Roy’s life was nothing special. The only thing commendable was the last few moments when he saved a mother and her child from a drunk driver.
…
It’s really an egg! Damn it, what kind of monster have I become? Did I fall into Hell instead of making it to Heaven??
Join Roy as he ventures through various worlds with the Custom Made Demon King System—a system that allows Roy to draw anything he can imagine and create it through exchanging souls!

A piece of divorce paper sent Xia Xinghe into a state of destitution. However, a car accident later, she transformed into a professional hacker with more money than she could ever spend. All those that have belittled, bullied and laughed at me, please line up, I’ll show you what the meaning of face-slapping is! Wait, wait, wait. That guy over there, the ex-husband that I no longer have any relations with, don’t cut in line. What, you want to help me face-slap these people? “Not only that I will help you face-slap myself!” The wickedly handsome man with billions of dollar in estate raised his own palm to slap his own face without reservation!

- Description from Novelupdates