Augmented Human C4-621 is a mercenary Armored Core mech pilot who goes by the stolen callsign Raven. They have undergone extensive biological and cybernetic operations that have augmented their AC piloting skills and limited their ability to experience human emotions. Under their Handler, Walter, they are an independent mercenary operating on the planet Rubicon 3. Their AC, LOADER 4, is a tan midweight biped with a rifle, pulse blade, and missiles. They have a voice in their head, named Ayre.