Skeleton Knight, in Another World - Chapter 11Volume 7 -

When an era came to an end, various forces set foot in cultivation to compete for immortality. A young boy who spent most of the time sleeping got lucky in the troubled times and became an unparalleled immortal who could cover the sky with a snap of fingers. Was he going to live forever?

- Description from Novelupdates

Corporate slave Alexander dies with only one regret—not finishing the fantasy novel in his hands. Fate has a twisted sense of humor when he awakens as Alexander Flamingo, the perverted villain destined to be expelled and killed in that very story!Armed with complete knowledge of the original plot and a mischievous “Harem King System,” Alexander plans to rewrite his fate. No longer the one-dimensional pervert of the novel, he'll use his future knowledge to manipulate heroes, seduce heroines, and rise from disposable villain to the true mastermind of this world.The system grants him power through every relationship he builds—but can this calculating reincarnator use his second chance to avoid his predetermined death and become the ultimate Harem King? One thing's certain: this story won't follow the original script.

Xiao Yu, who was a student from modern Earth, accidentally transports to another world and becomes the lord of a territory. Facing an unfavorable situation, he vows to take back his family business, build his new territory, kill all of those who covet his wealth, and dominate the world!