Friends Graham Aker and Billy Katagiri are two of several antagonists of the series; one is a Union ace pilot and the other is a mobile suit developer respectively. After the death of Professor Ralph Eifman and Howard Mason, Billy uses one of the GN Drives to upgrade Graham’s Flag unit in order to fight the Gundams. Graham battled Setsuna F. Seiei with his GN Flag, but he lost, receiving scars on the right side of his face.
I’m happily surprised to find a cosplay of these two! Billy is one of my favorite characters from Gundam 00! Maybe I will try to look for more of his cosplays now. Thanks again to Remi for sending this in!