Naruto: I Can Take People Through the Ninja World in the Future - Chapter 42: The First Rinnegan Test, Am I Actually Magneto?

One day, I woke up only find out that I’d become a Demon Lord, an individual responsible for protecting a dungeon. The world I’d been spirited away to was one filled with violence. Gigantic monsters wandered through it and competed with each other each and every day for the right to survive. I had no choice but to strengthen my dungeon’s defenses in hopes of living another day—or at least that was what I’d thought. For some odd reason, I instead ended up spending my days in relaxation and bliss.

Shen Zhixian transmigrated into a book as a cannon fodder master who hatefully severed his disciple’s spirit root. This disciple fell into the devil’s path and returned to make mincemeat out of him.

Shen Zhixian just happened to transmigrate into the last moment of the master’s captivity, and then he was reborn again.

After rebirth, he devoted himself to fostering and supporting his disciple, only to discover later that his disciple was also reborn.

Even worse, the disciple still retained the memory of his life before rebirth.

Shen Zhixian: …Disturbed.

Afterward, he realized one truth: Being a master is a high-risk occupation. Not trivial at all!

- Description from Novelupdates

Luo Yi, a high school dropout in his original world, was isekai’d into the world of the Witcher 3. Starting out as a weak boy named Roy in the village of Kaer, Lower Posada, he was determined to grow stronger, no matter what it took. The first step toward becoming a legend was to kill. And his first kill was… a rooster. ‘You gain 1 EXP.’ Of course, Roy had his own cheat system like all the other isekai protagonists. His first step to becoming a legend started now…