Getting reborn: I will make a harem this time. - Chapter 21: Rune magic

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.

[Congratulations, you have unlocked the SSS-Rank Job: The Shutter Summoner.]—Jaden Cross, a young man who earns his living by completing photography challenges given to him by his social media followers, was on his way to complete his new challenge for today.His challenge? To capture a picture of a smoking hot MILF, however, as he tried to complete his challenge, some 'unexpected' events led to the end of his life.But fate decided that his end was still not here, as he woke up in a wide grassland with his camera in his hand.His first thought was to take a picture, and as he did so, a chime rang and a blue screen appeared before him.[Binding Host with the Summoner Codex.]His camera captures anything, and his grimoire keeps all of it stored for him, allowing him to summon anything anytime and anywhere.Follow him as he captures World-Ending Calamities and places that even Gods were wary of to uncover the mysteries behind his transmigration.[Congratulations, you have captured the SSS-Rank Fairy Queen.][Congratulations, you have captured the Banished Site - Tower of Crimson.][Congratulations, you have captured the SSS-Rank Witch of Possibility.]

Euri was quite passionate about wanting to become a perfect corporate slave.But after being forced to explore the sentient game infesting his miniscreen, Euri realized that he had stumbled upon an opportunity anyone on the planet would kill for. While the entire human civilization on Planet Nen struggled to deal with the superior lifeforms plaguing the extraterrestrial planes beyond their world, Euri could compete with them all for power by just playing this game!A side-gig that didn’t conflict with his dream of climbing the corporate ladder—how generous can fortune be to bequeath this opportunity to him.Transcending the spatial laws, transcending human notion of cultivation, transcending the rules of Cosmic Development Bureau, Euri began a series of crazy experiments that could perhaps destroy the millennia-spanning schemes of the most advanced civilizations controlling the macrocosm.When interrogated about this fiasco, Euri answered the way a perfect corporate slave should. “Full credit for this goes to my boss, who provided me with the opportunity...”