Biocores: The Legendary Weapon Designer - Chapter 25: Preparations

Vergil, a 21-year-old young man, leads an apparently simple life in a somewhat troubled world. His family is also simple—although his father is no longer alive, his mother has always been by his side, despite being a bit... aggressive. But that's not so unusual nowadays, right?Everything changes drastically when Vergil, after an unexpected death, awakens as a demon. To his surprise, he discovers that he has accidentally married beautiful Pure-Blood demonesses.Now, he will discover how the world really works from a Demon's perspective.

Emperor Xianwu ninth reincarnation, only to break through the shackles, was besieged and killed by masters from all walks of life.

Fortunately, a ray of divine consciousness traveled across thousands of planes to the earth and entered the body of the dead young man, just to get rid of the anger in his heart and to regain that peerless peak!

- Description from MTL

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.

On the wedding day, her fiancé and his lover had a love affair and eloped. Her eyes were dim, she seized the man in front of the Civil Affairs Bureau.”To sum it up, your bride is not here, my groom ran off, wouldn’t it be better if we… fight together?”. Before marriage, she said, “Even on the bed, between me and you, there will not be anything!” After the marriage, he said, “Do not try, how do you know?”