Between using Brave and Hero, I for one prefer using Hero.
ブレイブ - Brave < ヒーロ - Hero, 勇者 - Yuusha vs 英雄 Eiyuu is how I see it.
Unless it's explicitly stated that he is a "Brave", I would rather see Hero, since as Anreon said, it would be strange to read "Oh, brave brave!"