MTL - My Doomsday Territory (My Apocalypse Domain) - Chapter 618 Main universe and plane

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

Upon opening his eyes, Muyang realized that he found himself in Dragon Ball’s world filled with dangerous people like Vegeta, Frieza, Cell, Majin Buu.

However, decades later.

“Captain Ginyu, let’s run away, we are no match for him!”

Jeice looked back in panic.

“Lord Frieza, the demon has caught up again.”

“He even destroyed our home planet.”

“This bastard!”

Frieza looked at Muyang with bloodshot eyes filled with anger, but sadly, there’s nothing he can do, even he’s no match for Muyang.

“Come on, show me what you can do.”

In the vast and boundless continent Cangtu, there were ancient sects governing the Ten Old Domains, unworldly immortal clans beyond the Blue Sky, and primordial demon gods dominating the dark abyss that together created a great number of brilliant stories over the long course of the history.

Amamiya Hiroto is unlucky. His life consisted of misfortune after misfortune, culminating in an unlucky death during an incident on a school boat trip, trying to save a girl he barely knew. After death, he met a god of reincarnation who requested that the hundred or so dead passengers—one of them being the girl he tried in vain to save—be reincarnated into another world.