Re-Birth Of A Genius. Creator/Destroyer - Chapter 834

In this world, orphans or just anyone without any hope for this world can apply to become a “walking target”. Their sole purpose is to be a practicing dummy for the students of the sect who train to become “Demon Hunters”. These students need “walking targets” to test their training on living, walking beings of flesh and blood.
In exchange, they will be provided with food & shelter.
Their existence value is lower than a slave, but if they manage to survive a few years they can receive a life long pension.

Xiao Han is such a “walking target”. One time he witnessed a powerful Demon Hunter disposing a demon. When the demon died, a fragment of the demon that managed to escape entered Xiao Han’s heart. No one saw that, and even Xiao Han himself only felt some discomfort for an instant.

But that thing in his heart soon gave Xiao Han visions, and the first one is of a cultivation method which allows Xiao Han to absorb damage to enhance his body. A perfect cultivation method for a “walking target”.

- Description from Novelupdates

Reincarnating into the world of Jujutsu Kaisen, he became Gojo Satoshi, the twin brother of the strongest sorcerer, Gojo Satoru. That should mean he’s destined to be the most powerful Jujutsu sorcerer, right?Unfortunately, fate had other plans. Nearly killed by Satoru in the womb, his cursed energy was devoured before he was even born. But at that moment, he awakened the [Shinigami Fusion System].Since he couldn’t become a Jujutsu sorcerer, he would forge a new path, a Shinigami with Heavenly Restriction!Thus, Gojo Satoshi, born without cursed energy yet possessing the legendary Six Eyes, became the true nemesis of Jujutsu sorcerers.

Go out with a bang. That's what my dad always used to say.If you're going to die in a world like this where people can add all these crazy modifications to their body, at least take a few out on the way.“Zero what the hell are you doing?” A kid with a wimpy voice asked.“Taking care of business, obviously.” I responded with a bit of an irritated tone.“Can you please get off of me...” A man asks, tears streaming down his face.People fear power and money. That's how it's always been, and this piece of garbage is one of those people.But none of this matters if no one knows how I even got to this point. Where Humanity truly began it's biggest stage of evolution.Humanity.exeThe City of Kairox is where everything runs through. Drugs, weapons, illegal cybernetics, you name it. One day I want to be the one who controls all of that.But I've been dealt enough of a shitty hand that I think it's about time I start dealing myself. Anyone can rise up in the streets with enough determination and strength.So, I'll rise up amongst this filth and make sure that I'm on top.

Shi Jin once read a book. It was supposed to be about satisfying the desire for vengeance.