Sovereign of the Three Realms (WN) - Chapter 4: Go Thrash Yourself

Zhang Xuan traverses into a foreign world and becomes an honorable teacher. 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 weakness would be automatically compiled. Thus, he became formidable.

“Emperor Haotian, why don’t you like to wear underwear? To think that you’re still an emperor, can you pay more attention to your image?”

“Fairy Linglong, if you continue to suffer from insomnia, you can always look for me. I have a way with lullabies!”

“You as well, Qiankun Demon Lord, can you cut down on the garlic? Do you want to stink me to death?”

…

This is an incredible story about the heritage between teacher and students, cultivating and guiding the world’s strongest experts.

Throughout heaven and earth, I alone am powerful

One minute, she was spiraling out of her scooter, watching in horror as her fried chicken flew into the horizon. The next minute, she was signing the contract to become a mother to his sons while staring into his glacier blue eyes.“The contract is effective as of now” He announced, as he dropped the pen. His brow was lifted challengingly and his voice reverberated around the room, bounced and sent zings of electricity down her spine.She tilted her head to a side, studying him covertly as she smiled menacingly. She was going to make him regret his decision.Let the games begin..!

I exist in the darkness, disappear under the bright light, and will eventually devour the sun and turn into the shadow of all things… Known by people as the indescribable terror of darkness; the king of shadows; the dark day; the existence of the shadow of the world , is still just a somewhat special high school student, facing a weird death game…

- Description from novelbuddy