The Reincarnation of the Strongest Exorcist in Another World — S1 E1 - The Strongest Exorcist

On the verge of death, an exorcist decides to reincarnate to lead a perfect life. He is reborn as Seika, the youngest of an aristocratic family. While nobility and magic go hand in hand, the young boy, devoid of mana, must face the mockery of his family.