In 2514 of the New Era, the apocalypse came. A world-class phenomenon appeared. Many strong mutated beasts have been wandering around the world since then. Humans are under deadly threats. They can only struggle for life. The one who will save everybody and protect the world from collapsing is... an average-looking barber from the slum? (Source: Webnovel)

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!

In the new galactic era, the Alliance's last general Lin Jinheng was assassinated and killed. Five years later, on the ragged and defeated Eighth Star System, people live in fear of the Black Hole Four. Only that Principal Lu is crazy enough to dare harass them occasionally. A mysterious chip is the start of the chaos, two people left Beijing ß at the same time for different reasons, not knowing it was about to be reduced to ashes by space pirates bent on revenge. Centuries of peace is obliterated in an explosion of fire and blood. And this is only the beginning. (Source: Bilibili, translated)

*Note: Chapter count includes 3 extras.*