The Butcher of Gadobhra - Chapter 67: The day before.

At the age of 12, Naruto Uzumaki gained the extraordinary ability to traverse between his home world, the Ninja World, and the mysterious world known as the Soul Society.Naruto's DiaryKonoha Year 63, March 15: I seem to have died [crossed out] I seem to have died and come back to life.Konoha Year 63, March 16: The weight of this new existence crushes him. A return to life offers no solace, and he questions whether it might have been better to remain dead.Konoha Year 63, April 1: Desperation sets in as Naruto searches the Soul Society for his parents, only to discover that this world is not connected to his own. His parents are nowhere to be found.Konoha Year 63, July: The dream of becoming Hokage fades, as Naruto finds himself detached from the village that once held his heart. The desire to become a Shinigami grows stronger within him, spurred by the hope of discovering the true Soul Society of his world and reuniting with his parents.

Sixty Years ago, one middle aged man brought a Qilin that looked like a pug and a mandarin duck that looked exactly like a duck, walking into the Imperial City of the Central Plains for the first time.

Haruma Kazuki is a cursed (or maybe just deeply unfortunate) high school student whose lewd, panicked, or absurd thoughts literally manifest in reality — especially when he tries not to think about them. The more he denies or avoids feelings, the more chaotic and trope-heavy the consequences.

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