I Become Karna With a Million Times Crit System In Mahabharata. - Chapter 125 124. Need A Bow

Due to an unexpected turn of events, Xia Fei consumed a Super Gene Optimization Fluid that bore no brand, expiry date, instructions or stated its place of origin.
Our story begins here…

A gigantic mouth appeared in the sky and swallowed the entire Earth, scattering the shattered fragments everywhere.“Welcome to the Myriad Heavenly Hunting Grounds, your talent is the Lord's Cottage.”Earthlings received the developmental ability called Lord's Cottage, beginning their struggle for survival in the Myriad Heavenly Hunting Grounds.Fang Jie, holding the initial item 'Faction Conversion Command', gently tapped on the undead faction. Starting with the undead fission talent, he could make his subordinate undead split and increase in value, and the talent could also be upgraded.

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

Kai is the hardest working warrior in his generation... and the unluckiest. In a world where most people receive magical skills, classes, or cultivation, Kai has nothing but his wits and his strength. His only choice will be to forge a new path against fate, no matter where it takes him.

Savage monsters pour endlessly from the wasteland, threatening the survival of civilization itself. They say that human strength isn't enough and only those gifted with destined powers have a chance of making a difference. Kai is hungry to fight in that war, to be someone who matters. That hunger will take him across a world stranger and more terrible than he could possibly have imagined.