Naruto System in One Piece - Chapter 400

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

“How can such an unscientific thing be possible?”“If it's true, wouldn't we be able to rule the world?”“You think so, don't you, Mr. Gin?”“By the way, could you please sign an autograph for me?”“Use your real name.”————Since the disappearance of high school detective Shinichi Kudo, the death rate in Beika City has been increasing.But it doesn't matter, Hayashi Yoshiki will take action.He will make the whole world keep up with Beika City's pace.

Li Xiao Yao left S.W.A.T to become an ordinary security guard. While working, he happened to enter the VIP room and found Lin Wang Er still in the middle of changing. As revenge, she took him on a ride and kicked him out of the car.

After hours of walking, Li Xiao Yao finally managed to get back home just to be kicked out of the house. He then got an offer from his previous supervisor to become the bodyguard of the Tian Xi group CEO’s daughter both in game and in reality. But unknown to Li Xiao Yao the girl was actually…

- Description from Novelupdates

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.