Staying Alive Cautiously in the Celestial Realm and Becoming the Strongest - Chapter 599 - : The Secrets of the Upper Realm

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

Enigmatic hands, spectral frame, and one cunning strike just like the swing of the Grim Reaper. The Supreme Assassin takes on the mystical world, and how his legendary tales sets off, progressively ascending the altar to becoming the best.

- Description from Novelupdates

Dragon 5th is a powerful lord with incredible martial arts, and yet is wasting away from a fatal disease. The only medicine which can cure his sickness lies in the clutches of his venemous ex-wife, Madam Lovesickness, and is guarded by 7 dangerous killers, fugitives of the martial world. To retrieve the antidote, Dragon 5th hires Liu Changjie, a skilled martial artist who loves drinking and women, but has a mysterious past. All is not what it seems in this wuxia heist story.

Kim Jeongjin, an editor of a publishing company on the brink of closing due to bankruptcy, ends up transmigrating inside a fantasy novel as the incompetent youngest son of a wealthy family.

And here he thought that he should live a rich life in this life…

“Why was I given a high-level skill? Don’t even bother!”

All I ever wanted was for famous detectives like Sherlock Holmes or Arsène Lupin to appear in my dreams and share their wisdom. But instead, why am I hearing the voices of notorious serial killers in my head, guiding me to solve a string of mysterious cases?