Manadeshi ni Uragirarete Shinda Ossan Yuusha, Shijou Saikyou no Maou toshite Ikikaeru

In a world torn by conflict between humans and demons, the renowned hero Fried has spent years fighting to protect humanity. As one of the most powerful mages of his generation, he has trained numerous students in the art of combat magic, including his most promising pupil, Lyle. Together, they stand at the forefront of the ongoing struggle between the two races. However, the tides of war are unpredictable, and Fried soon finds himself caught in circumstances beyond his wildest imagination. When he awakens in unfamiliar territory with no memory of how he arrived there, a mysterious demon girl greets him with an unexpected title. Now facing an entirely new reality, Fried must navigate complex allegiances and reconsider everything he thought he knew about the nature of good and evil. As he adapts to his new position, Fried will encounter challenges that test not only his magical prowess but also his understanding of justice, loyalty, and what it truly means to be a protector. The boundaries between friend and foe blur as he embarks on a journey that will force him to question the very foundations of the war he's been fighting. (Source: MU)