Naruto: Kurotsuchi Mayuri - Chapter 279 - 190 : Retreat!!

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 imperial edict and the family’s calculation, the sweet, adorable her met the cold him that was up high. She became his little princess consort. Everyone said that Prince Ying of Western Xuan Empire was shockingly ugly, cold-blooded and ruthless. They laughed at her that she had mistakenly entered the tiger’s den with her life in danger. But she just laughed that everyone in the world couldn’t see the wider picture, and were stupid and ignorant. The ugly appearance was actually beyond gorgeous, cold-blooded was actually gentle and sweet. She only wanted to hide him away and not allow other people to peep at him. “Big Ice Cube, take off your mask and let this princess have a look!” She propped up her chin with saliva flowing down.

“Want to look?” A certain person’s lips hooked into a devilishly charming smile, saying. “Then first, hand over some down payment…” This is the story of a sweet adorable female and a two-faced male’s journey to fight enemies and kill strange things, while pursuing a romantic relationship that was absolutely full of loving spoiling, hilarity and hot-blooded action.

- Description from Novelupdates

In the distant Eldrathis Galaxy, a vast and uncharted frontier teeming with ancient ruins and deadly secrets, humanity is a small fish in an ocean of monsters. But that doesn’t stop treasure hunters like Clara Dravenmoor, a brilliant and reckless archaeologist, and the Safira's crew, from chasing lost relics buried in the void.Her latest mission? Recovering a priceless artifact from the ruins of Zhaaros, a hostile planet plagued by nomadic warlords and nightmarish creatures. But what she finds isn’t just a relic.It’s him.A pale, otherworldly man, locked away for centuries in a high-tech sarcophagus, covered in mystical markings and dripping with an aura of power that defies reality.He looks confused. No memories. No idea why he was trapped there.But he doesn't look angry.He looks eager.Excited to follow Clara in the Safira through the vast and magnificent galaxy.

Five hundred years later, a superhuman talent cultivated by the state perished during a mission, and his soul transmigrated, taking possession of the body of a young master from a prominent family who suffered from an anxiety disorder. From that moment on, his extraordinary life began, spanning across various fields such as business and medicine. Wherever he set foot, others could only look up to him.