VII Dual is a dummied status effect originally meant to appear in Final Fantasy VII. Despite the fact that Dual doesnt apply any visual change on the characters models, those afflicted by Dual will lose HP on a constant rate. In past games this status effect is known as Sap. It lasts until the end of battle. As with most other statuses, the only things that protects a player from it are Peerless, Petrify, and Resist.