Madou Kensei -Densetsu no Kikan-

The hero who holds both the strongest title in magic, Mage, and the strongest title in swordsmanship, Sword Saint, returns to a world 1000 years after becoming a legendary figure!! Balua Westgarden, the Magic Sword Saint who once mastered both magic and swordsmanship and etched his name at the pinnacle of human history, challenged the absolute demon king Giranher in a decisive battle for the survival of humanity. However, due to the interference of mysterious forces, both Balua and Giranher lost their lives. For 1000 years, Baluas soul was bound to the world by regret for dying halfway through his journey. But when Direa Westgarden, a boy who admired the Magic Sword Saint, was attacked by monsters and left on the brink of death, Balua returned to the mortal world by borrowing his body.