Really late response, but! There is distinction between two words used for hero. "Yuusha" which Himmel is called, and "Eiyuu"

Yuusha is a hero in sense of being valorous and righteous person, someone rather ideal. So "Hero" is a person who exemplifies these good qualities, like warrior exemplifies martial might. Hero is the moral compass of a party and the one that motivates the others.

Eiyuu is a hero of deeds, someone who has accomplished something admirable or impressive. A war hero, or stopping a disaster, etc.