Dxd: A demon Among Devils - Chapter 62: []:Metatron

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

For non anime fans- Yandere is extremely possessive girlsIn an open world MMORPG game called Stellaris Fantasia Online, me and my partner we're rising to the top, killing other players, farming loots and so on....But, yes, this partner of mine won't let me play with others.... even with my friendswhy? because she's a Yandere....Its so irritable that I unfollowed her.... well that decision hurts me too, since she might turns out to be a hot onee-san (older woman)But as soon as I attend the class, my homeroom teacher is in bad mood...Why??Just read the title....

Nile Santos lived a life of sacrifice — always stepping aside, always giving others the best gear, always following orders without question. In the end, none of it mattered. His comrades fell, his body was broken, and he died a meaningless death in the final battle against an unstoppable force.But fate isn’t finished with him.Offered a second chance by the very beings who led him to ruin, he’s thrust back in time with all his memories intact. This time, though, he’s not playing the role of a noble shield. No more selflessness. No more obedience. No more being a pawn.Armed with future knowledge and a will forged in failure, he vows to rewrite his story — to take everything for himself. Skills, loot, allies, power… all of it. It’s time for one man to climb to the top, no matter what it takes.Author's other storiesThe Unrivaled Holder: Rise of the Dragon Monarch - 3rd Season OngoingI Ascend Alone - Ongoing

I found a girl of unknown origin outside; she claims to be a time traveler from a post-apocalyptic era.Great calamity is imminent, with abominations spreading across the land, human civilization annihilated, and even the world itself shattering, all beyond redemption.As for myself,I am considering how to confine this beautiful girl, who has temporarily lost her powers, within my home.