I Was Reincarnated as the 7th Prince so I Can Take My Time Perfecting My Magical Ability Episode 1 SUB at Gogoanime

Synopsis: A mage, lacking both talent and lineage, is burned to death by the magic he loves. He's reborn as Lloyd, seventh prince of the Saloum Kingdom, with his past memories intact. One day, in a forbidden library, he awakens a demon that wields ancient magic... (Source: Crunchyroll)