Later, He Became A Royal Healer - Chapter Ch125.5 - NSFW.

Traversing into another world, Zhang Xuan finds himself becoming an honorable teacher.

Along with his transcension, a mysterious library appears in his mind.

As long as it is something he has seen, regardless of whether it is a human or an object, a book on its weaknesses will be automatically compiled in the library.

Thus, he becomes formidable.

“Emperor Zhuoyang, why do you detest wearing your underwear so much? As an emperor, can’t you pay a little more attention to your image?”

“Fairy Linglong, you can always look for me if you find yourself unable to sleep at night. I am skilled in lullabies!”

“And you, Demon Lord Qiankun! Can you cut down on the garlic? Are you trying to kill me with that stench?”

This is an incredible story about teachers and students, grooming and guiding the greatest experts in the world!

- Description from Novelupdates

The first time Yan Zhaoge crossed worlds, he landed in a martial warrior civilization that was at the peak of prosperity. He ended up in the book storage building of the the Divine Palace, which collected and preserved the classics of the entire world from all fields of knowledge. However, a world class calamity struck soon after and even the Divine Palace was destroyed.

Yan Zhaoge’s soul once again crossed over, but this time he arrived in the same world, except countless years have passed.

With his brain full of rare books and classics from the era of peak prosperity, Yan Zhaoge’s second crossing over to the present era was like a gamer who was used to playing hell mode suddenly finding himself playing the game on easy.

That was just way too awesome.

But before that, he needs to fix a certain problem.

“I’m not a main character? In fact, I’m actually the main character’s love rival and the antagonistic Mr. Perfect senior martial brother? This script is wrong!”

- Description from novelupdates

When Ye Mo suddenly woke up, he realized that everything around him seemed to have changed: He has been transmigrated into the modern Earth where spiritual energy is scarce. His pretty master from his former world was nowhere to be seen. Most importantly, he found himself in the body of a young man who has been abandoned by his clan for an embarrassing reason…

- Description from Novelupdates

Kai was a 17-year-old dropout. A NEET. A background character in real life with nothing to his name but bitterness, novels, and guilt. After his parents died, he gave up on the world. People were fake. Dreams were pointless. And that one novel he kept reading? He hated it especially the main character, June. Perfect, noble, always standing tall. Everything Kai wasn’t.Then, one night, a voice asked: “What if you did meet June?”He said yes, half-asleep and half-mocking.Now he’s trapped in the novel. Isikeid. But he’s not June. He’s not a hero. He’s not even in the main cast.He’s an extra in the background of a world he knows too well and he’s had enough of watching things play out the same way. This time, he’s going to change everything. Whether the world likes it or not.