MTL - Magneto of Hyuga - Chapter 31

Junpei Takeda, a high school student, is childhood friends with Noriko Tatsumiya and is bullied by Kido Shouta. One day, while bullying Junpei, they (Junpei, Tatsumiya, & Shouta) were suddenly summoned to a different world by the whim of “God”. Summoned Heroes with cheats, or so he thought. But it turns out Junpei’s stats were even worse than an average farmer. Tricked into a deathly labyrinth by the only one he trust, he walks the journey for revenge.

Finding an ancient treasure was not as fortunate as one might expect. As soon as Bai Rouyun had left the grave, countless sects and hidden families set out to kill her for the sake of obtaining her treasure for themselves.

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