It's a piece from the Ulthring's Set from the Dragon Knight Saga game. "The mighty Armour of Ulthring was once worn by the mad wizard after whom it was named. He died in a great battle against the united forces of mankind, and afterwards the Black Ring got hold of the pieces that formed the armour. They were then distributed among their most deserving members, and redistributed when a piece holder died. To wear even part of the Armour of Ulthring is considered to be a great honour, even though this honour usually means the wearer becomes the center of Black Ring jealousy and greed."