MTL - Deliberately Contaminated - Chapter 12

[Simulation shall commence.]On this fateful day, the world was stunned by the appearance of ancient animals that were supposed to have gone extinct for millions of years. Huge sinkholes appeared in every corner of the world, becoming a tunnel for the ancient animals to emerge to the surface.Humans have found an answer to one of the biggest mysteries in human history. Hollow Earth is real. Here, humans will wrest their lives to explore this new world that has existed for thousands, if not millions, of years underneath them.Before the start of his exploration, Clovis came across a place called ‘Another World Mall.’Dwarven Sword, Magical Elven Clothes, or Giant Race Toy? Everything can be found in this ‘Another World Mall.’As an aspiring Subterranean Explorer, how would he utilize this ‘Another World Mall’ to become the greatest explorer of all time and find the truth about the simulation?

The protagonist of the collapse of the three former civilizations is Dr. Mei. What is the end of logic, the strongest brain, super intelligence, this is the story of the strongest scientist of Honkai with knowledge of the moon becoming the god of science!

- Description from novelbuddy

A man who was once called the world’s strongest agent ended up becoming a teacher after his retirement, to train a new generation of agents. After many years of training his disciples, he was killed at the age of 60 by a secret organization’s ruse and was reincarnated in another world with his memories intact. Though he was surprised by the existence of magic and the strange species in that world, he quickly adapted to his condition as a newborn and took advantage of it. He acquired special magic and gained a massive amount of strength thanks to his rigorous discipline, in order to reach his goal: Resume his career as a teacher which he left halfway through in his previous life. This is the story of a man, who, based on the memories and the experiences of his previous life, became a teacher who travels through the world with his students.

He—an enigmatic and cold-blooded soldier with a mysterious background.
She—a ruthless and bloodthirsty spy.