Stubborn Love of a Roguish Scion - Chapter 369 - : Do You Not Know? I Am Your Brother-In-Law

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.

One day, I woke up only find out that I’d become a Demon Lord, an individual responsible for protecting a dungeon. The world I’d been spirited away to was one filled with violence. Gigantic monsters wandered through it and competed with each other each and every day for the right to survive. I had no choice but to strengthen my dungeon’s defenses in hopes of living another day—or at least that was what I’d thought. For some odd reason, I instead ended up spending my days in relaxation and bliss.

This story revolves around a boy who was sent to a dark, mysterious parallel world in the body of his beautiful senior sister known as Lily. The lone girl ran into the night parade of a hundred ghosts the very day she arrived; seeking survival amongst the warrior’s dispute in a chaotic world, and forging her own demon sword! This is an unimaginable other world adventure!

The leaves of the chess game beside Lanke, and there is no one playing chess among the old trees
Xing caused Tian Yuan’s first son, and then looked back at the vast mountains and seas
When he woke up, Ji Yuan became a half-blind beggar in a dilapidated mountain temple.
A real person has a sword and a magic stick has a mouth, which is the foundation for Ji Yuan to settle down in this terrifying world.

- Description from novelbuddy