Protomateria

The Protomateria is a special type of Materia in Dirge of Cerberus -Final Fantasy VII-. It is, like the Black Materia and White Materia, a special one-of-a-kind Materia created by the Lifestream that lets the holder tap into the power of the Weapon Omega.

The Tsviets sough the Protomateria to control Omega, and by uploading the memories of Lucrecia Crescent into Shelke the Transparent, discovered it was held by Vincent Valentine. They attacked Vincent several times, demanding the Protomateria, but Vincent was unaware of what they meant. Eventually, in a fight in the Shin-Rav Mansion, Rosso the Crimson defeats Vincent in combat and seizes the Protomateria from inside Vincent's chest. At this time, Vincent transforms into Chaos without warning.

At this time, the connection between Vincent, Chaos and the Protomateria is explained. The Protomateria allows the holder to access the power of Omega or Chaos, and when Vincent was mortally wounded by Professor Hojo, Lucrecia implanted the Protomateria into Vincent's body to save him. However, Vincent needs the Protomateria to control Chaos, and without it his mental defenses are weakening and he is losing control to Chaos.

Using the Protomateria, Weiss the Immaculate, under Hojo's control, takes on the power of Omega. However, Vincent eventually defeats Weiss using Chaos, learning to control him without the Protomateria, and after winning takes the Protomateria back into himself.