Shortly after the initial invasion of Earf, despite what victories were achieved by the land forces, it was realized that a new land combat avatar was going to be soon needed. The Aries was the Empyrean Corporation's submitted unit for combat trials and testing. Greater emphasis was placed upon higher ground speed and rough terrain handling, being able to adjust to either urban combat or fighting on open plains. At the same time priority was also placed up on designing a machine that was less expensive to produce and maintain in the field.
The Aries was a popular machine with its pilots, and several units made effective use with it in several operations. For a while it seemed that the competition between it and the Pegasus was not going to come to an end at any time soon, but production on both avatars were canceled in favor of the newer Taurus.