The wiki uses "Brave" because of Daigo's line, "Brave da ze!" (spelling may be incorrect). Yuusha can be translated as "Brave" or "Hero" so the pages were correct to begin with. Because of Daigo's line referencing bravery, we use Brave. All those edits have been reverted accordingly.
I don't know what you were trying to do there, but you made such a mess of the page that I had to roll it all the way back. You were missing spaces after commas, making unnecessary links, some things very badly worded....I tried to clean it up but just couldn't. There was even a chess pawn symbol in there that served no purpose.
While I very much appreciate you trying to help the wiki, please avoid adding unnecessary images in the future. You recently have been adding several images to articles that did not help in any way. The wiki is not an image hosting service. Please review this page for more information.