The Runesmith - Chapter 24 Little Goblin Slayer to the rescue.

In a universe where the memory of Wisps has faded, one of these elusive beings finds itself amidst human society two billion years in the future. But what exactly is a Wisp? No one knows anymore. Join this whimsical and unconventional Wisp on a hilarious journey as it navigates an unfamiliar world, seeking its place and rediscovering what it means to be a Wisp.

A young man with an extraordinary mind is off on an exciting adventure when he mysteriously wakes up in the body of a feeble slave-guy in a different, rich in quirks world.

The main character, a selfish jerk, would use extreme means to achieve his goals. However, he never allows his base instincts to overrule his sense of decency. He always pays back both good and bad deeds.

Will his (terrible/excellent) mentality help him make a fresh start? Will he get through misfortunes and hardships of the new world?

[You have successfully devoured your target.][Your strength has increased by 250.][Your speed has increased by 200.][Your defense has increased by 300.] [You have acquired the Golden Immortal Bloodline.][You have acquired the Chaos Beast Physique.][Your cultivation has increased.][You have accumulated Madness.]The Era of Chaos is upon the Cosmos once more leading to various kinds of Chaotic Rifts spawning randomly.Meanwhile, a 26-year-old actor on Earth, Pascal Margrave, transmigrates into the body of Caelum Goldheart. Upon transmigration, he becomes the host of the World Devouring System - a system that allows Caelum to quickly become stronger by absorbing the power of anyone he kills.However, things are not so simple. Caelum quickly realizes that while he is the [Host] of the World Devouring System, he is not its true [Master]. Failing to complete the system's milestones within the designated time will lead to his soul being tortured in the Netherworld for all Eternity.Join Caelum on his journey as he attempts to take control of his own fate, uncovers the hidden plots around his transmigration and becomes the dominant power of the Cosmos.

Xiao Yu was humanity’s greatest genius, a scientist whose intellect surpassed all others. He saw the signs of Earth’s impending doom a decade before it happened, warning the world of the catastrophe to come. But instead of being hailed as a savior, he was ridiculed, dismissed as a madman by his peers, and ignored by society.Realizing that nothing could change humanity’s fate, Xiao Yu made a decision. He turned his brilliance toward survival. Using knowledge decades ahead of human science, he constructed the first true interstellar battleship—not for humanity, but for himself. And when the end came, he did what no one else could. He abandoned his mortal body, fusing his very soul with the ship’s central computer and escaping into the endless void.Now, drifting through the vast and indifferent cosmos, he is the last remnant of a dead civilization. But he refuses to let humanity vanish without a trace. Why was Earth destroyed? Was it truly unavoidable, or was there something more sinister at play? To uncover the truth, he must push beyond the limits of human science. His battleship is just the beginning. Through relentless technological advancement, he will evolve, forging a warship that can traverse the stars, a fleet that can reclaim humanity’s lost legacy.The universe is vast, filled with unknown civilizations, ancient mysteries, and dangers beyond imagination. But Xiao Yu will not stop. He will find answers. He will ensure humanity’s flame is not extinguished.The journey into the unknown begins now.