Its in-game description reads "Armband blessed by a goddess." This brassard shares a small ressemblance with the Athena's Armlet except it's blue instead of yellow. It also has some high elementals stats. This brassard is powerful, and when it's charged it delivers a lot of power. You can only find the Goddess Brassard in dungeons' chests, and therefore you can't buy it or invent it. It's a high-tier weapon (Tier 7) : it'll gain 6 Synthesis Points (SP) per level-up.