Astra was a founding member of the Imperial Guard and first clashed with the
X-Men over the fate of the Shi'ar Empress
Lilandra. Later, when
Deathbird was Empress, she commanded the entire Imperial Guard to fight the combined forces of the
Starjammers and
Excalibur so that she could claim the power of the
Phoenix Force for herself. During the battle, Astra surprised
Shadowcat with the ability to hit her in intangible state, since she could match her molecular density.
During the crisis that came to be known as
Operation: Galactic Storm, Astra was amongst a small contingent of the Imperial Guard that defended Lilandra against the
Kree super-team known as
Starforce. Astra was also with the Imperial Guard when they defended their Empress Lilandra against an assassination attempt from the
Inhumans, who were under the control of
Ronan the Accuser at the time.