Warrior-Servants or Warriors were the second-lowest rate in Forerunner society. As their name suggests, they were responsible for defense and warfare in the Forerunner Ecumene. The Warrior-Servants were presumably all subordinate to the Warrior-Servant Corps. They utilized many different war machines, including War Sphinxes and Seekers.
A particular group of Warrior-Servants known as the Prometheans created "Warrior Keeps" known as Cryptums. They were also strong proponents of the Mantle. While Forerunner society was peaceful by nature, Warrior-Servants were ruthless in executing warfare against other races, as they believed that defying the Forerunners was to show contempt for the Mantle.