Harry Potter and the Surprisingly Competent History of Magic Professor

Cassian Rosier, once a mocked and dismissed member of a Sacred Twenty-Eight family, finds his life irrevocably altered when a simple light spell becomes his last chance. This event triggers a profound change: the Cassian known to his family vanishes, replaced by a man from our world. This new Cassian, possessing no magic but extensive teaching experience, awakens with only faint recollections of the Harry Potter series. Thrust into a body with a damaged reputation and lacking any magical ability, his sole objective is survival. Forced to lecture, Cassian improvises by teaching Lumos, a spell he doesn't know. Miraculously, as hundreds learn from him, mastery of the spell floods his mind. This leads to the awakening of an ancient Lumos variation and the emergence of foreign memories. These memories offer insights into long-forgotten magic, but some are dark and perilous, blurring the line between wisdom and malevolent influence. Now a professor at Hogwarts, Cassian must navigate the demands of his pureblood family, the distrust of his colleagues, and his own burgeoning power. Each spell he imparts increases his mastery while drawing him closer to an ancient past that threatens to consume him. This is a snarky, slow-burn power fantasy about an accidental professor who excels at teaching, unlocks forgotten spells, and balances ancient memories with family politics and potentially dangerous students.