Rusty is one of the Elite ZAFT pilots known as "Red Coats". He is part of the Le Creuset Team during their Attack on Heliopolis. Rusty was going to steal the Strike, but is killed by an EA soldier named Hamana before he could enter the cockpit; Athrun Zala avenges his death by killing Hamana. Not much is revealed about him other than the fact that he thinks more like Athrun and Nicol Amalfi; meaning he questions whether what they are doing the right thing, however, it's also said that his nature is more like that of Dearka and Yzak, hence why he is also described as the "glue" that held the team together in the novelization of Gundam SEED - he is able to relate to all of the members. In the novelization of Gundam SEED, he does tease Nicol a little bit, and, in the first manga volume by DelRey, he did express views that he thought that Naturals were a bit foolish. In Gundam SEED, Rusty's face wasn't shown (except in a photo on Athrun's billboard and in a group photo after their graduation from the military academy) and had no lines, hence viewers didn't get a glimpse of his character until Special Edition was released. In Gundam SEED Destiny, Yzak Joule, Dearka Elsman and Athrun visit the memorial sites of Rusty Mackenzie, Miguel Aiman and Nicol Amalfi laying flowers on all three.
Contrary to popular belief, Rusty does in fact have a parent on the supreme council and ranked 5th at the ZAFT academy upon graduation.