I Was Reincarnated as the 7th Prince so I Can Take My Time Perfecting My Magical Ability Tensei Shitara Dai Nana Ouji Dattanode, Kimamani Majutsu wo Kiwamemasu

The qualities valued most in the study of magic are bloodline, aptitude, and effort. There was one sorcerer who, despite his deep love for magic, was born a commoner and thus lacked the bloodline and aptitude for it. As he died an unnatural death, he wished he had studied magic more while he had the chance. Then, he was reincarnated as Lloyd, the seventh prince of the Kingdom of Saloum and one blessed with a strong magical bloodline. Reborn with all his memories intact, along with the perfect bloodline and immense talent, he was determined to enjoy his new life, using his extraordinary magical abilities to master the study of magic that was beyond his reach in his previous life!

(Source: Crunchyroll)