i think that badges should be able to give boost to players if you get lets say the undead stalker badge you get an attack boost on a creatures considers undead. the higher badges on the same line like undead slayer gives higher boost to wizards. badges that are gained by defeating areas or worlds should give you an all around stat boost against all mobs and bosses in that world or area.
This is a very good idea that I myself was about to post, it doesn't make sense to have all these fancy badges just for show, we should give them actual worth and actual value.