Rakudai Kenja no Gakuin Musou: Nidome no Tensei, S-Rank Cheat Majutsushi Boukenroku

Ephtal reincarnates in a magical world but dies talentless and frustrated. Reborn 400 years later with his memories intact, he finds magic has declined so drastically that his once-mediocre abilities now make him the strongest mage alive.