Omega Weiss is the final boss of Dirge OF Cerberus -Final Fantasy VII-. When Deepground kills many innocents to call the strongest Weapon, Omega, it appears over Midgar. Believing the mass deaths are a sign the planet is dying, Omega prepares to gather the Lifestream and depart into space, leaving the planet a lifeless husk. Omega was taken over by Weiss, the Deepground commander. Vincent Valentine, a human with the power of Chaos, goes inside the Weapon to fight Weiss directly. Vincent defeats them both, destroying Omega and saving the planet.