落第賢者の学院無双～二度目の転生、Ｓランクチート魔術師冒険録～

Ephtal, a human from modern Earth, reincarnates into a world where magic is real and pours his new life into becoming a master sorcerer, only to discover he's utterly talentless and dies in anguish. He gets a second chance: reborn once more, he keeps every memory and skill from his failed first life, arriving in a school where the era's magic has grown so weak that his old 'failure' level now makes him unstoppable. This manga adapts the light novel of the same premise, published under a different subtitle.