Rebirth in One Piece as Deputy Captain - Chapter 511

Like many medical students, Li Yong just succeeds finding an intern job in hospital with great efforts and yet still is going broke. He even has no money to pay the rent. However, by coincidence, he acquires a magic power of clairvoyant vision and rich experience from 80 medical experts, all because of a pendant passed down from his parents. With the magic power, he can see through human’s skin and finds out any illness beneath without any physical touching or examination! Since then, his life has been tremendously changed. Love, fame and wealth become within reach for him…

- Description from Novelupdates

In the 30th century, Tyler Rustel is an eccentric and visionary genius, renowned as a brilliant inventor. His life, however, comes to an abrupt end when a small experimental nuclear reactor explodes in a series of unforeseen events. Yet, death is not the end for Tyler. He awakens in a body that feels both familiar and foreign—a parallel version of himself in a completely different universe.This is not a world of technological progress or orderly civilization. Here, twisted gods roam the cosmos, shaping realities according to their cruel whims. The moral laws that governed his previous world do not exist. This is a magical universe, one marked by brutal betrayals, interdimensional wars, and endless massacres. The balance between the forces that rule this cosmos is fragile, and Tyler finds himself at the center of schemes involving powerful entities and boundless ambitions.However, Tyler is no longer an ordinary man. Upon awakening in this new world, he discovers that a fragment of his technology has survived with him: an advanced artificial intelligence system capable of analyzing, adapting, and enhancing anything, provided it has the necessary data. From magical weapons and arcane spells to alchemical techniques and enchanted jewelry, everything can be optimized under his supervision.Armed with this technological advantage in a universe dominated by magic, Tyler quickly realizes the potential of his unique position. While others struggle to survive, he schemes to conquer. Driven by his sharp intellect and a questionable sense of morality, Tyler embarks on a ruthless campaign to achieve magical supremacy and subjugate all worlds around him. He seeks neither redemption nor alliances. His ambition is clear: to rule everything and everyone as a tyrant, to amass an immense harem of women, and to father one million children to establish his legacy across all realms.

It begins on the mountain.

With the glint of a knife, a flash of steel in the hands of a sworn brother. A betrayal.

Stabbed and pushed down the mountain, Zi Chen lied within the red-stained snow, left to die.

This is where it begins; he is given life by lightning,
baptized by thunder.

Those who had once betrayed him should all suffer in his cruel revenge.

- Description from Novelupdates

He became a teacher at the best magic academy in the empire.
….For being mistaken for someone else.