Maou-sama no Machizukuri! ~Saikyou no Danjon wa Kindai Toshi~ - Volume 1 Chapter 21

It’s the vacation of a lifetime, a trip to a remote island filled with geniuses and murder.

Before his death, he was the only sword cultivator in the whole world, who dedicated his entire life to the path of sword immortality.

When he opened his eyes again, the world had completely changed. He began to cultivate the path of sword immortality again, slaying the heavenly way, shattering the universe with his will, and achieving the realm of sword immortality!

- Description from Novelupdates

“Primum non nocere.”

The youthful Qin Ye was born almost a century ago, but thanks to immortality granted to him by the ‘fungus of aeons’ he can pass for a high schooler.