It's a piece from the Aleroth Archmage Set from the Dragon Knight Saga game. "Unique and incredibly powerful, the pieces of this set were fashioned by Aleroth's first Archmage: the famed Mardaneus. Though he was buried in his paraphernalia, graverobbers must have desecrated his last resting place for soon parts of the set were sold on the black market for exorbitant prices. And so they sometimes fell into good hands, though more often into bad ones."