Naruto : Gamer System - Chapter 27 : Enemy Attack

What happens when a scientist from a futuristic world reincarnates in a World of Magic and Knights? An awesome MC is what happens! A scientist’s goal is to explore the secrets of the universe, and this is exactly what Leylin sets out to do when he is reincarnated. Dark, cold and calculating, he makes use of all his resources as he sets off on his adventures to meet his goal. Face? Who needs that… Hmmm… that guy seems too powerful for me to take on now… I better keep a low profile for now. You want me to help you? Sure… but what benefit can I get out of it? Nothing? Bye. Hmmm… that guy looks like he might cause me problems in the future. Should I let him off for now and let him grow into someone that can threaten me….. Nahhh. *kill*-

Alternative: Leylin is transported from an advanced technological era into a medieval world— except there’s magic. Equipped with “only” his quick wits and an A.I. chip fused to his soul, he sets out to become the most powerful magus the world has ever known. In a land divided into the Light and Dark Magi, the weak can either be cattle or disposable slaves. Only the strong can determine their lives, and only they have the luxury for virtue. Yet strength is only a tool for Leylin, like any other. His goal, in the end, is his own.

Everyone said that Yi Qing was the number one Sword Cultivator in the world, with a swordsmanship and cultivation that no one could surpass. Whether it was when he was cultivating in the Lower Realm, or when he was in the Ten Heavens of the Upper Realm, he has always been undefeated.

Yi Qing laughed and said: “That is because you do not know of my Master. If we speak of cultivation, I am not as good as she by a long mile. Thinking about it, at the start, out of the ten Heavenly Emperors of the Upper Realm, my Master beat up nine, and the one left was myself.”

“Master? You actually have a Master! Who? How come we never heard of it?”

“My Master is…. Eh? Master? Master! And my Master? Has anyone seen my Master?”

A person next to them quietly raised her paw. “I am here!”

- Description from Novelupdates

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.

Wazu was an ordinary townsman who shut himself off in the “mountain” because of an unfortunate course of events. After 2 years, he decided to come down from the mountain to meet with people. But there were various misunderstanding about the “mountain” which he shut himself off in. And then he repeatedly had encounters with people. And after that. . .