Reaper of the Drifting Moon - Chapter 127: Light Novel: Volume 6 Episode 2

She was originally an assassin. After rebirth, she was reduced to another world’s Di family’s most inferior concubine-born daughter. With an extremely hideous appearance and no way to cultivate, she was the object of everyone’s humiliation and bullying.

A high school student that has lived as a mob-character ―― Mimori Touka

Anyone who could construct a stable Spell Model could become a Wizard — that was the Wizards’ ultimate secret! Having been given a new life as the son of an aristocrat and armed with a super quantum computer from his past life, Spell Models came as easily as breathing to Merlin. With this overwhelmingly huge advantage, would Merlin become the greatest Grand Wizard of all time?

- Description from Novelupdates

Once upon a time, an Alchemist Grandmaster from the World of Immortals accidentally took possession of a playboy, who hailed from a rich and powerful family, and became a student in the middle of his midterms.