As Sukuna in Invincible - Chapter 26: Through the Eyes of Madness

What do you do when your brother dies because of some entitled assholes? You go undercover.My real name? Clare. But at school, I’m Clause—just another guy blending in. Disguised. Watching. Yes, a boy. No, it's not an all-boys school—I'm just deep undercover, hunting down the bastard responsible for my brother’s suicide. Nobody—and I mean nobody—messes with my precious brother and gets away with it. They better pray I never find them, because when I do? Death will be a mercy, and trust me—I don’t do mercy.And as for the egotistical Alpha and the narcissistic Vampire Prince? They can go fuck themselves. I don’t do mates, I don’t do claiming, and I sure as hell don’t do them.

A prestigious senior mechanical engineer in the industry, Xu Yi was sent to a world dominated by magic.

In a world with an almost non-existent industrial system, how can Xu Yi display his value?

When magic collides with modern technology, when magic merges with machinery, that is the beginning of this story.

A High School Boy without friends, Odamori Tooru reincarnated into a Fantasy World after a bus accident on a School Field Trip. The job that was drawn 『Slavemancer』a Cheat occupation that dominates the minds of other.

Once upon a time, there was a beauty who met nonstop misfortune. This unfortunate man hurried to hug a golden thigh…

Coming from the end of days, the ‘excluding eating there’s only eating in his brain’ Little Useless Eater transmigrated to a ghost story world where it’s difficult to preserve his life. Good that, not only does his IQ explode the meter, all attribute points are also entirely placed on his face, letting him rely on his otherworldly beauty to find a thick and sturdy big golden thigh. Hugging from world to world, finally, from a pitiful thing being oppressed by demons and monsters on every path, he evolved into a vexatious ghost!

- Description from Novelupdates