Arc 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, Arc spearheaded 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. Arc's squad 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. Arc was subsequently defeated by the X-Man the
Beast.