For weapons, the GN Arms was designed to utilize different weaponry between its fighter and mobile armor (MA) form. Although armed with a specialized silhouette, it has limitations depending on its form. The units are armed with two sets of weaponry: standard and customized.
The standard weaponry is featured in both units; both are armed with a pair of Large-Size GN Cannons and GN Claws. The cannons are hidden at the top-rear hatch, right on top of the thrusters. The top hatch provides protective shielding for the cannons as it is the most powerful (comparable to Gundam Virtue’s GN Bazooka) and vulnerable (its destruction can destroy the entire craft) in combat. The GN Claws is a three-pronged weapon inherited from the Gundam Avalanche Exia Dash armor system. It is a melee-type weapon, meant for close range bird-of-prey style attacks. However, the original GN Claws was built with beam sabers for extended reach and had greater attack capabilities against its enemy target(s); CB engineers (for some unknown reasons) removed that ability, limiting these particular GN Claws for mainly latching and tearing against its target(s). The claws are located at the underbelly of the GN Arms; they’re folded within the lower platform until deployed. However, while its standard weaponry makes it formidable, it is its specialized weaponry that gives the GN Arms its unique combative qualities.
GN Arms E's customized equipment are its pair of Large-Size GN Swords and the GN Guns. The swords are larger versions of Exia’s swords; they’re GN particle-laced vibro-swords designed to cut through large targets (ex: mobile armors, spaceships, asteroids, etc). However, they’re specifically designed to puncture through GN Fields in case their enemy(s) managed to acquire GN technology. Designed after Exia's primary weapon, the GN Guns are built behind the sword. Although called guns, their firepower is comparable to Dynames' GN Rifle. The overall weapons silhouette gives the pair of gun-swords a focus in close-quarters combat (CQC), but balanced for mid-to-short range firing solutions.
In terms of systems, the GN Arms is powered by GN particles. The units are built with GN Condensers to store a limited supply of particles; its pilot must be mindful of its particle reserves or risk a power-down in a compromising tactical position. However, the units are designed with a docking system that connects their respective Gundams’ GN Drive to help recharge their particles for extended operation usage. Celestial Being engineers also installed a GN Field for added protection against enemy attacks. While not built into the GN Arms, either units can utilize the Trans-Am System through their Gundams during emergency situations to temporarily enhance three times their normal combat capabilities. However, its overall systems risk reduction in performance after all its particles are expended.
For combat, its native form is a fighter: GN Arms Mode. Able to fly in outer-space and Earth’s atmosphere, it can only utilize the GN Guns and Large-Size GN Cannons for high-speed heavy assault combat; it relies on its speed to flank and shoot down its target(s), similar to traditional aerial dog fighting. Unfortunately, its remaining weapons and abilities are offline in this form and its weapons are locked in place, lacking flexibility and dynamic firing solutions. As fixed weapons, they are limited to shooting down its target relative to the body positioning of the unit itself. While the units can deploy a GN Field, it was never used in this form; it suggests GN Arms either can't deploy its GN Field or has limited usage in its fighter form. Another weakness are the units' limitations in traveling between Earth and space; to compensate for those weaknesses, the Assault Container can be deployed to for enhanced tactical operations.
Celestial Being engineers realized the GN Arms have limitations exiting Earth’s atmosphere and its overall mass is too great to fit into a linear train for a ride back into space. While not designed for the sole purpose of being an atmospheric shuttle, the Assault Container (AC) is a heavily armed tactical mini-MS carrier that can safely house Exia and GN Arms through some of the most treacherous conditions; the GN Arms bears little involvement in operations when docked.
When combined with the AC, the GN Arms’ overall systems are not utilized other than its thrusters (providing additional thrust power to account for its added weight into the AC). Its overall body is safely shielded within the confines of the AC along with its respective Gundam (although they’re not docked together in any special configuration). Combined with the Gundam and powered by its GN Drive, the pilot of the GN Arms is transferred through a special lift and ported over the AC's helm for manning its flight controls and weapons; the AC is in complete control and the GN Arms is just along for the ride. However, should the container become compromised, the pilot can immediately transfer back into the GN Arms and eject Exia to escape and can recombine as a MA for advanced combat.
When transforming into GN Armor, the pilot expands the unit into a large exo-suit combat system. The GN Arms opens in such a way that Exia simply "falls" its back onto the GN Armor, lock in place, and utilize its systems in a matter of seconds. The cockpit folds up and rotates to the rear of its frame. The mid-section expands and exposes a special docking module that docks directly with Exia's GN Drive Cone. The lower modules fold out to reveal its GN Claws and foot platform to dock with Exia's legs. Its fixed weapons are now unlocked and widened for Exia's arms to dock and utilizing it as an extension of its arms.
In GN Armor combat, the armor is co-piloted by Lasse and Setsuna; the full aspects over its controls are not fully defined and its capabilities is based on observation. In battle, Setsuna has full control over Exia while Lasse seems to handle mainly propulsion and the MA's cannons during combat. Setsuna's influence over the MA seems to be limited to its control over the armor's GN Guns, Large-Size GN Swords, and the GN Claws; he relies on Lasse for evasive maneuvers, firing the cannons, and deploying its GN Field against enemy fire. Should the the GN Arms becomes critically damaged, Exia can simply pull itself out of the MA and resort to MS combat.
Overall, the GN Arms units had proven their value in combat, however, it would be the last of its kind. While Celestial Being engineers continued to produce new support units in its GNR series, Celestial Being ceased creating of any kind of mobile armor. Instead, Celestial Being engineers focused on developing equipment to enhance the combat capabilities of their Gundams; it eliminates the need for mobile armors since their individual capabilities can surpass them. However, the combat and technical data of the GN Arms was used to help CBS-74 Ptolemaios 2, a multi-purpose warship that supplements and succeeds the GN Arms as the Gundams' most powerful combat support unit.