The Guard and the X-Men subsequently clashed once more when the Shi'ar sought to end the threat to the universe posed by the cosmic entity known as the Phoenix, which had assumed the form of X-Men member Jean Grey. Following the orders of their emperor, the Guard clashed with the X-Men and were on the verge of winning when the band of interstellar freebooters known as the Starjammers arrived to turn the tide of battle in the X-Men's favor. Gladiator was amongst the first of the Imperial Guard encountered by the team of superhuman mutant adventurers known as the X-Men who sought to rescue the Princess-Majestrix Lilandra from her insane brother, then-Majestor D'Ken. The fiercely proud Gladiator is the leader, or praetor, 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.