Some 17,000 years ago, Gaia's home galaxy was sacrificed to prevent access to the Citadel of the Universal Amalgamator (COTUA), a device on the edge of reality able to unite the universe into a single consciousness. As the only mutant with power to activate the Amalgamator, Gaia protected it from others, ultimately becoming COTUA's guardian and prisoner. Aside from allegedly visiting Earth 600 years ago, Gaia apparently remained chained to the COTUA until M-Plate
(the combined form of Marius/Emplate, Claudette and Nicole St. Croix) kidnapped the power-duplicating Synch
(Evert Thomas) to copy Gaia's powers so M-Plate could merge everything in the universe.