Manta is a member of the Imperial Guard, a multi-ethnic group of super-powered alien beings who act as enforcers of the laws of the Shi'ar Empire. She was one of eight Imperial Guardsmen chosen to battle the team of superhuman Earthling mutants known as the X-Men over the fate of Phoenix, a primal force of the cosmos that had assumed the form of the X-Man Jean Grey.
Later, after the formerly-exiled Deathbird had usurped the Shi'ar throne, Manta was amongst those Imperial Guard members who clashed with the British team of costumed adventurers known as Excalibur and the team of interstellar freebooters known as the Starjammers over the fate of the then-bearer of the cosmic Phoenix Force, the alternate future daughter of the X-Man Jean Grey named Rachel Summers.
During the war between the Shi'ar and Kree Empires, Manta was one of a small contingent of Guardsmen that were dispatched by then-Empress Lilandra to retrieve the famous Nega-Bands of the Kree warrior Captain Mar-vell from his tomb.
Manta was later one member of the insurgency team that attacked the X-Men on the orders of their Empress Lilandra, who was at the time under the mental control of Charles Xavier's mutant twin sister Cassandra Nova. The attack was halted by the arrival of his fellow Guardsman Smasher who managed to convince the Guard of the true threat. Together, the Guard and the X-Men managed to defeat Nova and free Lilandra.