MTL - Very Happy - ~ most important

Sue Kirin was a loser. Thirty years old with no hope for advancement at his job and no redeeming features except one, Magic. For as long as he could remember Kirin had dedicated his life to practicing the Arcane. Unfortunately, when he was passing down his knowledge to his niece, she lost control of her power resulting in a backlash of vicious energy that resulted in her being sent to the hospital, her life in critical danger.

She is an international ace agent,An amazing doctor, God of Assassination, However due to a box she accidentally rebirthed and became an ordinary junior high school student. Weak and incompetent, That scum woman wants to put her head into the toilet. The gambling father, borrowed a lot of money and now they are being chased by loan sharks for debt? There is also a group annoying people in her life. The reborned Yunxiao sneers: I want to know how to write the dead words! She returned from the wind, high-profile attack, if people dared to bully me, they are courting death!

What the heck? She, a famous doctor from the 23rd century, turned into a village peasant girl of a different world!

Her grandmother was cruel and vicious. Her aunt was very mean. So, to have a meal and clothing every day, she, a famous doctor had to pull up her sleeves to do farm work, treat patients, and abuse the bullies!

What? Grandmother need money for her illness? Cousin has no money to get a wife? Cousin needs to borrow money for his studies?

Roll! Roll as far as the history can go!

- Description from Novelupdates

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.