The Sacred Blacksmith

Once upon a time, there was a tragic war, in which the power of the devils was involved. After the war, the devils' power was banned and the world was restored to peace. Cecily Campbell is a knight, who has been looking for a blacksmith to repair her old sword given by her father. One day, she saw a man fighting with a ruffian who used the tabooed devil's power. The man defeated him with one blow of his weirdly shaped sword. The man turned out to be a blacksmith called Luke. (myanimelist.net)