High School DxD - Volume 1 Chapter 5

Roy’s life was nothing special. The only thing commendable was the last few moments when he saved a mother and her child from a drunk driver.
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It’s really an egg! Damn it, what kind of monster have I become? Did I fall into Hell instead of making it to Heaven??
Join Roy as he ventures through various worlds with the Custom Made Demon King System—a system that allows Roy to draw anything he can imagine and create it through exchanging souls!

Lin Fan awakens to a world where chaos reigns, stripped of family, status, and safety. But within the turmoil, he discovers a powerful secret—the Beast Abilities system in his mind.With every threat he eliminates, he earns vengeance points, enabling him to level up his physiques.From the humble Wild Rabbit’s ability—[Rabbit's Hearing], [Swift Foot], [Magnificent Leap]—to the ruthless strength of the Wolf—[Hunter Instincts], [Iron Claws], [Leader of the Pack]—and the Ape’s raw power—[Climb Trees], [Strong Arms], [Inhale Qi]—Lin Fan hones his skills with every battle.Years later, as the feared grand master of a prestigious sect, he looks back in wonder. Who would have believed that his rise to greatness began with the unassuming gifts of a wild rabbit.

He was the continent’s strongest and most revered alchemist, Ye Zifeng. He was under one person and above millions. However, due to an unpredictable event, he had died. After his rebirth, he had become the supertrash of the Ye family and suffered disgrace. To make matters worse, he had an argument with his fiancé that led to the break off of his engagement. In this second life, he will work to change his own destiny. He vows to return to the peak of the world, trample on those who laughed at him and rewrite his legacy!

- Description from Novelupdates

I became a scientist for an evil organization.…But I’m too competent.