Kouritsuchuu Madoushi, Daini no Jinsei de Madou wo Kiwameru

Zeph Einstein, a magician who dedicated his life to mastering Crimson magic, is awarded the highest honor by the Crimson magicians. The next year, he uses a new magic that evaluates a sorcerer's true potential and discovers his Crimson magic is weaker than his other abilities. Realizing he has spent years on his least effective skill, he is overwhelmed with regret and develops a magic to send himself back in time. He awakens in his younger body and joins forces with Milly, a gifted magician, and Claude, a skilled female swordsman. Together, they begin a journey, hoping this time Zeph can learn to master his magic in a more effective and efficient way.