Casey’s close companion, Angel, is the avatar of the Angelfyre SI. She is an intelligence that exists within the SI and is responsible for assisting the Angelfyre pilots in all manner of operations, intelligence assessment and mission execution, including piloting and training. Although Angel is completely synthetic, she experiences deep, human-like emotions unlike any other artificial intelligence in existence. The feelings were completely foreign to her, causing constant conflict within herself as she tried in vain to suppress them. Casey played a critical role in helping Angel with dealing with her emotions, and this led to them becoming very close companions. Because Angel is constantly connected to Casey through her ISD (Interconnect Sync Device), they share experiences at a level that is simply incomprehensible for the average person. Just like Angelfyre, Angel’s origin was shrouded in mystery, and she had no memory of anything before Casey found and activated her.
Angel’s intellect is impossible to describe. She has the combined knowledge of almost the entire United Systems and computational power that is orders of magnitude greater than even the most powerful computer systems of the time. Despite this, she occasionally faces situations that she cannot figure her way out of, and Casey once again plays a critical role in supplying some good old-fashioned human perseverance irrespective of the ridiculously small odds of success that Angel may be seeing.