Chief Kim and Assistant manager Choi - Chapter 37

As the head disciple of the number one sect in the world, Luo Jianqing had a brilliant reputation. He was the most respected senior brother of his junior brothers and sisters: the last disciple of the cultivation world’s number one cultivator, Luo Jianqing greatly respected his master’s teachings, not crossing his limits by even half a step.

Afterwards…… he was stabbed to death just like that by the main character with his sword. His master’s sword.
Luo Jianqing: “……”
The heavens wants me dead, yet I refuse to die! See if the will of the heavens is more fearsome, or if the will of my sword is more stubborn!

Wu Yin: “Jianqing, I have something to say to you.”
Luo Jianqing: “Master, I also have something to say to you.”
Wu Yin: “… you speak first?”
Luo Jianqing: “You speak first.”
Wu Yin: “I like you.” / Luo Jianqing: “I want to top you.”
Wu Yin: “……”

- Description from Novelupdates

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.

In this world, mystery and the supernatural never depart.Those who, with bodies honed through thousands of trials and indomitable wills, break the chains of life and pursue human limits in modern cities, are known as martial artists.Under neon lights, swords clash. At the tops of towering buildings, friendships are made through fists.Among mountains and peaks, heroes discuss their ways.Here, martial artists who have broken the “seven physical limits” carve their godlike names under the heavens, stunning both the ancient and modern worlds and making the stars shine brighter!Here, the once-in-a-decade “World Martial Arts Tournament” broadcast is the highest rated program globally, where martial artists fight for their nation and themselves!Here, martial artists, with their mortal flesh, combat dark spirits and mythical beasts in life and death battles to protect their homeland's civilization.Here, every true martial artist unswervingly believes:“The martial way is boundless; my body is unfettered!”

Liola—the best assassin in his world—has vowed to kill no more. He was being chased by an assassination organization when he accidentally dropped into a parallel universe: through a dimensional gate and into poor teenager Kaiser’s apartment. Instead of going to the government shelter for lost dimensional travelers, Liola and Kaiser wind up going to school together.

Liola has been trying his best to live the life of an ordinary person, but after certain things happen one after the other, he begins to realize that being an ordinary person could be harder than being an assassin.