Monstra 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. Part of the division of the Imperial Guard known as the Superguardians, Monstra was involved in the Guard's first strike on the team of superhuman mutant adventurers known as the X-Men after his Empress Lilandra, under the mental control of Charles Xavier's mutant twin sister Cassandra Nova, had ordered the destruction of all mutants on Earth. Along with fellow guardsmen Arc and Squorm, Monstra captured two of the X-Men, the optic-blasting Cyclops and the helmeted healer Xorn, and took them to the orbiting Shi'ar superdestroyer to await execution. In the ensuing clash with the X-Men, Monstra was clawed across her eyes by the Beast before finally falling to the fighting fury of the feral Wolverine.