In the Shi'ar Empire, the elite military and homegrown security comes from the Superguardians, or Imperial Guard. The Guard calls upon the best of the best, champions from each of the many worlds throughout the Imperium to serve together on behalf of the Empire. Some Guardsmen represent with the unique powers of their race, while others are mutants or superhumans with abilities uncommon to their people. The Imperial Guard are almost blindly loyal to the Imperium, serving just as fiercely under rulers such as D'Ken, Vulcan and Deathbird than under Lilandra.
Subgroups of the Imperial Guard exist to some degree. First were the Borderers, who operated on the outskirts of the Shi'ar Empire, while the main Guard protected the interior of the realm and often acted as direct bodyguards to the royal family. The Praetorians were elite agents chosen personally by Emperor Vulcan, and operated parallel to Gladiator's command. Finally, the existence of Subguardians and Superguardians has been established, as entire classes of lesser Guardsmen exist for different types such as Smashers, Fangs, Mentors, etc, with only one Guardsman of each type acting as Superguardian representative in the Imperial Guard.
(The original Imperial Guard was man-to-man based off of DC's Legion of Super-Heroes. Most new members over the years have also followed this pattern.)