Cage is a Marine Drill Sergeant stationed at the marine base on Tragedy.
Cage isn't a war hero, or at the very least he doesn't like to think he is, but he's been at this stuff for a long time. He knows that war is hell and that there's a chance you may not come back, but he believes that's a worthwhile risk for doing what's right. He decided he'd become a Drill Sergeant in order to make sure the new recruits are prepared for what's ahead. So far, he's seeing mixed results.
Not much is known about Cage's history, other then being from South Blue.