Three Great Generals

The Three Generals of the Guardians are elite members of the Imperial Guardians specially chosen by a committee consisting of the Emperor, the Marshal, and the Emperor's Advisor. They're selected not just based on combat capability but also on leadership and strategic capability. They're normally selected from the Double 0 Numbers but lower ranked members were sometimes appointed by recommendation of the Advisor.

Duties
The Generals, as their name would suggest, serve as the commanders of the empires armies. Each member was assigned to lead a different division; Calgurio led the Armored Division, Gradim led the Beast Division, and Yuuki Kagurazaka led the Composite Division. Prior to the formation of the Composite Division there existed the Magic Division which was led by Gadra.

Additionally, the generals all serve as the strongest personal fighting force within their respective divisions. They're gifted with God-Grade equipment passed down generation to generation since ancient times and as high-ranking members of the Imperial Guardians, naturally outclass regular soldiers.