Kikansha no Mahou wa Tokubetsu desu  

A Returner's Magic Should Be Special, 帰還者の魔法は特別です, Gwihwanjaui Mabeob-eun Teugbyeolhaeya Habnida, Gwihwanjaui Mabeobeun Teukbyeolhaeya Hamnida

The world is facing imminent destruction after a ten-year war in the "shadow labyrinth." With few skilled magicians remaining, Desir Herrman is one of the last defenders against the formidable enemy threatening humanity's existence. However, even he seems powerless to stop it. Just as he believes all hope has been lost, he is sent back in time to his early days at the Hebrion Academy, where he studied magic. With this rare opportunity, Desir is determined to save not only himself but also his friends and comrades from their terrible fate. Armed with knowledge of what lies ahead, can his efforts make a difference or are they all doomed to repeat the same tragic destiny? This story is based on a popular novel.