Naruto: Unlocking Kaido Template - Chapter 160

In the tenth year after the new era, the world finally came to an end. Zhang Mu truefully waited for his death, but unexpectedly found that he had returned to ten years ago. With his memory about the future, he swore that he would change the calamitous history, saving the earth from being destroyed! Walking dead, zergs, evolvers, and various mutated animals… nothing can stop him! The first step is to retrieve his identity as an era merchant , then find all the treasures he can remember to enhance himself!

No one knows when the first Clough door appeared. All people know is that a new era began when it was pushed open.Fortresses, sublimators, pillars of star essence, three-dimensional armaments, infinite energy, who can escape the sweeping tide of the times?In the abyss, the reverse realm, the skins, the alien gods, the mad king, the rulers, and the dark creatures, all howl in madness!Inside the black mist, the demons and ghosts crawl forward as a cross-dimensional migration silently brews.

Calamity descends upon a a tranquil world in the black of night, transforming it into a death game! This a a true apocalypse, but this is not the end of humanity!

- Description from Novelupdates

Leon was your typical guy, perceived as weak in his school because his skills hadn't awakened, even though they usually did at the coming of age. He attended the prestigious Milham's Magic Knight Academy, where snagging the top spot meant automatic entry into the esteemed position of a Magic Knight in the country. Unfortunately, Leon found himself in the lower caste, labeled the most useless student. To top it off, he was tossed into a class that served as a sanctuary for oddballs and delinquents. Yet, he couldn't care less, as becoming a Magic Knight wasn't his goal.Everything shifted when he crossed paths with Shredica, a woman hell-bent on becoming a Magic Knight at any cost. Observing Leon's lack of ambition and his apparent detachment from the academy's pursuits, Shredica saw an opportunity. She decided to exploit him as a pawn in her ascent through the academy's hierarchy.Yet, unbeknownst to Shredica, Leon was not the complacent, unremarkable figure she presumed him to be.