Zero no Tsukaima - Volume 2 Chapter 6

Yan Qing’s sister, who has been sent down to earth, was schemed; designed to be a miserable female character in every life.

To save her younger sister, Yan Qing, a retired quick-transmigrator, full class man, once again set foot on the world shuttle journey to hardcore protect his sister and counterattack scumbags.

And then … ——

The real daughter who was kicked out of the House: sorry, my richest brother came to pick me up.

Abandoned White Moonlight stand-in: sorry, my elder brother said you lost your throne.

Face-slapped cannon fodder female partner: sorry, the country spoils my brother, my brother spoils me!

- 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.

Before his death, he was the only sword cultivator in the whole world, who dedicated his entire life to the path of sword immortality.

When he opened his eyes again, the world had completely changed. He began to cultivate the path of sword immortality again, slaying the heavenly way, shattering the universe with his will, and achieving the realm of sword immortality!

- Description from Novelupdates

There is a famous fairytale. A kindhearted girl whose father and stepmother got married and became a family of five with her two stepsisters. The poor girl who was condemned by her stepmother and stepsisters when her father died. The very fairytale, Cinderella.