Arifureta Shokugyou de Sekai Saikyou (WN) - SS Kousuke

The poor Commandery Princess is down and out. Her father died when she was young, and her mother passed away not long ago. Her grandfather, the only one she can rely on, is now at death’s door from his illness. Faced with the merciless uncle, the greedy aunts, as well as cousins competing to present the model of the worst relatives, the Commandery Princess could do nothing but feel depressed in heart.

The protagonist, Winnie (文尼), confesses his love to his childhood friend—the princess he’s been secretly in love with for years—but is brutally rejected in public. His heart shatters, he’s humiliated and ridiculed, and he collapses unconscious. When he wakes up, he vaguely remembers his past life’s memories and realizes he has transmigrated into the world of an otome game he played before. At first, he’s thrilled, thinking, “Nice! I must have been reincarnated as a villainous side character who disrupts the protagonist’s romance, right?” But then… surprise! He’s not just the villain—he’s the “Saintess”!

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.

Athena Grant,a human,dies in a car accident and becomes Eira Liora,an elf. Transported to the barren and cursed island of Luinmir, a once-thriving land now abandoned.A year ago,their King announced that the island,Luinmir would no longer be under the empire's control. It was well known that the land was barren and poverty stricken...She was abandoned both by her Kingdom and her Father.She wakes up one day with a system.“So what if they were abandoned and deemed cursed,she would show them all the highest peak of knowledge and development. The island's core is broken...fine,she'll get it replaced but this time,the island would become hers to keep,she would make sure of that.”