1x13 - The Legend of the Legendary Heroes

The magic knights of Roland killed Kiefer's older sister and captured Kiefer's younger sister four years ago, which then urged her to become a military double agent. After Kiefer saves two defenseless children in the midst of war against Stohl, Riphal Edia uses aggressive tactics of invasion by using a long sword hero relic in exchange for his left eye, claiming that he is waging wars to ultimately end the fighting against Gastark.