King of Kung Fu in School - Chapter 404 Not even a Fart

While returning home from a boring day of work, a black hole opened up in front of John and sucked him in. Before he was floating in the blackhole, a helmet latched on to him. "Uploading A.I under progress...Activating Survival Kit" A weird robotic sound appeared within the conscious of John and suddenly a white energy enveloped him... After opening his eyes, John noticed he was teleported to a whole new world. A world of magic and he was a user of a system. Arkon, the world John was brought too, was a medieval world which is 10 times bigger than earth. This new world held many new mysteries and this was the beginning of John's adventure. John will dominate and stir the world with his new system. Old technologies begone and use my advanced techys instead! Ha! you want to hold a politic, economical and military war with me? Sorry but my system is too broken for you all to counter.

When I read the development of the heroine getting stolen away, I left a malicious comment to the author.

But then I woke up later, and I’m now the villain who is supposed to steal the heroine.

Shiro Sakamaki was reborn into a new world with one simple goal: to live a peaceful, luxurious life free from drama.But when he transfers to a prestigious high school in Tokyo, he quickly discovers that his new reality is anything but ordinary. The city is a strange mix of supernatural forces, ghostly phenomena, and events that feel like they’ve jumped straight out of an anime.Before long, bizarre occurrences follow him everywhere, along with a series of beautiful, mysterious girls—from the arrogant, blonde twin-tailed exorcist, to the mysterious quintuplet sisters, to a passerby heroine with hidden powers.As Shiro gets tangled in the supernatural chaos, he realizes he’s at the center of something far darker. Cursed relics begin to surface, and Ancient, Evil Outer Gods—whose very presence bends reality—start to stir.Now, Shiro must figure out why he’s caught in this web of strange occurrences while trying to survive school and the surreal new world he’s been thrust into.

Klein’s greatest wish is to transmigrate to another world and live life in an isekai, just like in anime, manga and novels. However, fate is on his side and the typical truck that the main characters always carry in isekai runs over Klein. But, to his bad luck, he lived a few more days in the hospital and, just on the day he died, Klein heard a ⟨⟨-DING-⟩⟩ that he knew it meant. That was the day of his death, but also the beginning of his adventure into another world.