Dragon Ball God Mu - Chapter 50

—She is a girl with a bright smile on the battlefield.

With her silver hair fluttering in the air and dark eyes, the girl sprinted on the battlefield. Her name is Olivia, whose hands is stained with the blood of her enemies as she shows an innocent smile.

The deep knowledge and combat techniques of the entity who called itself a Death God has been branded onto her body. On Olivia’s 15th birthday, the Death God suddenly disappeared. Olivia enlisted with the Royal Army and started fighting in the war as she searched for clues.

Lunar Calendar Year 998. The Kingdom has suffered consecutive losses to the Empire aiming to conquer the entire continent. The innocent girl who lacked common sense will step into the battlefield as the “Strongest Chess Piece” of the Kingdom, and go down the path of a hero—!

HE WAS SUPPOSED TO AWAKEN A POWER. INSTEAD, HE AWAKENED NOTHING.Louis Lee is the son of two legendary Earth Defenders, but when the superpower evaluation test reveals that he's powerless, his world crumbles. Mocked, abandoned, and broken, Louis becomes a target in a world where strength is everything.But fate has other plans.When a devastating alien invasion shatters the city, Louis is abducted by the same monsters that once killed his parents.Subjected to a brutal experiment, Louis is implanted with a living alien core, a weapon to annihilate humanity at once but instead the core grants him incredible powers making him, half human and half monster.But now, Louis is Earth's only hope of defeating the invaders, but the more he uses the core, the more it mutates him, transforming him into something far more scary.

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

Xue Xi is forced to fall in love at first sight with this dangerous man on their first meeting. With death being the only other option, she makes the first move: