The Gundam AGE-FX is developed from Gundam AGE-3's combat data following the battle in the Mars Sphere. It reflects all the data regarding the Gundam's evolution, boasting the most powerful fighting strength in the history of all Advanced Generation mobile suits. Like the Gundam AGE-3, the Gundam AGE-FX's backpack can separate and function as a Core Fighter. Unlike Gundam AGE-3's Core Fighter, where it serves as its head, core control system and the main propulsion system, Gundam AGE-FX's Core Fighter only has the last two functions. The wear system used in previous Gundams is completely removed, and the suit is made as light as possible for increased maneuverability.
The "FX" designation stands for "Follow X-Rounder", and refers to the mobile suit being built specifically to keep up with the abilities of an X-Rounder pilot. The most notable weaponry of the Gundam AGE-FX is the 14 C-Funnels, which are wireless, remote-controlled physical blades that can be used for offense and defense, and they can only be controlled properly by an X-Rounder.