Regressor Takes Everything - Chapter 6

After she had transmigrated into the body of an abandoned wife of a little marquis in Ancient China, Su Nuan Nuan, a modern-day food lover was delighted!

She can finally achieve her dream of not caring about the outside world and focus on what she loves best — eating!

But the good times did not last long.

Her husband was curious about these new and exciting dishes, and threw her back into the inner palace.

Then… all hell broke loose!

- Description from Novelupdates

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.

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.

Worlds overlapped, and Alien Species descended.Strange entities emerged one after another, as the shadow of evil spread wildly.The calm of life was shattered, and Zhang Xiaoman, inside a fish's stomach, accidentally consumed a system named “World-saving Plan”.From then on, he became the only person among all humans with Extraordinary Power.…Inventing an ancient oath, he established a unique methodology, Cultivated Dark Energy, founded an organization, took Control of the Transcendent, and resisted invasions.Well, this is actually the story of how a Big Con Man bluffed his way into saving the entire world.PS: Contains elements of the behind-the-scenes, Cthulhu mythos.