One Piece: The Strongest Trait System - Chapter 4: [] : A Collection of Super Traits!

A century after the Spirit Qi Awakening, the world enters a new era. Humans are able to absorb the world’s awakened spirit qi, allowing them to tread on a new path—spirit qi occupations!

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates

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.

He—an enigmatic and cold-blooded soldier with a mysterious background.
She—a ruthless and bloodthirsty spy.