Re:Zero Kara Hajimeru Isekai Seikatsu - ReZero EX: Fortune Setsubun Hollow

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

Worlds overlapped, and Alien Species descended.Strange entities emerged one after another, as the shadow of evil spread wildly.The calm of life was shattered, and Zhang Xiaoman, inside a fish's stomach, accidentally consumed a system named “World-saving Plan”.From then on, he became the only person among all humans with Extraordinary Power.…Inventing an ancient oath, he established a unique methodology, Cultivated Dark Energy, founded an organization, took Control of the Transcendent, and resisted invasions.Well, this is actually the story of how a Big Con Man bluffed his way into saving the entire world.PS: Contains elements of the behind-the-scenes, Cthulhu mythos.

Cha Myung-jun, a sergeant who neared the end of his military service, found himself confined in the Ministry of National Defense’s bas**ent for over three decades due to his newly awakened abilities, just before the outbreak of war. Spending thirty years as the world’s most formidable blacksmith, wielding nothing but hammers, he skillfully outwits the watchful eyes of the Ministry of Defense to serve the war effort and reset the course of time. Now given a second chance at life, can he lead a successful campaign to avert humanity’s downfall and secure its salvation?