The Undead King of the Palace of Darkness (WN) - Chapter 42: Vampire Hunter Part I

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.

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!

- Description from Webnovel

[By the Author that brought you “Martial God Regressed to Level 2”]The Swordmaster, who unified the continent and vanquished the Demon King with nothing but his sword, thought he would live out his days peacefully in a world of tranquility.One day, however, he awakens 1,000 years later in the body of a distant descendant.In a world where magic is now held in higher regard than the sword, the empire has crumbled, and the imperial lineage has fallen into ruin.“More importantly, what is this pathetic excuse for a body?”He now inhabits the body of Kaylen, once known as a “walking slime”.With the demonic realm invading once again, he makes a vow:“Since I’ve mastered the sword, I might as well master magic too.”Thus begins the return of a transcendent being, armed with unparalleled magic and absolute swordsmanship, destined to save the world!

This story is centered around the man named Yi Ji-Hyuk, who has spent 1000 years in a Medieval Western fantasy-like world before returning back to the modern-day Earth. When he returns, he finds that his home is facing monster threats, and that humans with superpowers have appeared to protect the innocent people of Earth.

Doomsday comes, and human beings enter the heavenly world.
Ten years later, Yang Chen, who was betrayed tragically, returned strongly with the Tianyu bug. In this life, he vowed to make the betrayal pay the price. He has a powerful bug bonus, just like an open hang. Frightened to hear…

- Description from novelbuddy