Let Me Explain, Fairy - Chapter 109 - 100 Tianyan

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

A man with a lifelong martial arts background, raised in Asia due to his family's profession, moves to the US for education and work. He discovers Historical Medieval Battles through a colleague and becomes deeply passionate about it. He trains hard and becomes skilled enough to represent his country.During a competition, his armor fails, and he's struck in the head with a two-handed axe, seemingly dying. But is this truly the end?

He was reborn in the world of Naruto as a member of the Uchiha clan, known as Uchiha Genya. Born with the rare dual-pupil Sharingan, many saw him as a monster. Luckily, his father, Uchiha Kinya, was wealthy and influential, and he managed to protect Genya along with his mother Senju Yumi.Genya hoped for a peaceful life, but everything changed when he turned seven. The night of the Uchiha clan's massacre began.“You want to wipe out the clan and kill my father? Then don't blame me for fighting back”Uchiha Itachi: “Can your cursed eyes really break through my genjutsu?”“Dual-pupil Sharingan with six tomoe? How terrifying will you be when you awaken your full Sharingan? How many powers will you possess?””What terrifying strength... One punch can shatter the Susanoo!“That fateful night, Itachi slaughtered the Uchiha clan and defected from Konoha, but Genya managed to protect those loyal to him.Uchiha Obito: ”Genya can actually disrupt my Kamui?“Madara: ”A dance, you say? Ahem... Genya doesn't need to join!“Ten-Tails: ”This guy has more chakra than me!“

In a world ruled by mana and bloodlines, John White was born with none.Reborn from Earth into a noble family, he became the forsaken son of a duke (a bastard) bullied by siblings, ignored by servants, and banished at fifteen like trash.Two years later, he's dragged to a mana mine to be quietly killed by his brother's lackey. But fate has other plans.Deep underground, an ancient abyss-grade ring awakens. It merges with Earth’s forgotten technology with the world’s magic. Fueled by pure mana, it unlocks the Black Hole magic, granting him power never seen before.From a worthless outcast to a terrifying Void Lord, John begins crafting magical tech tools that warp reality itself. His enemies have no idea what’s coming.Will he burn his past to ashes… or rebuild the world in his own image?