Unlike the two other Crossbone Gundam units, the XM-X3 is drastically different. Instead of beam shields, it has arm-mounted I-field generators which could completely disperse beam attacks, even those from battleship-grade beam cannons and Variable Speed Beam Rifles. However, even after being used for so many years, I-fields still suffered the problem of overheating. As a result, each could only operate for 105 seconds before needing to cool off for another 120 seconds. Even when alternating between the two I-field generators, the Gundam would still be defenseless for about 15 seconds.
The chest armor is strengthened and features a pair of machine cannons to enhance its close combat abilities. The X-3's main weapon is the Muramasa Blaster, a large sword mounting fourteen beam saber emitters along its blade and a beam gun in its tip that can also function as a beam saber. The blades are powerful enough that only the X-3's own I-field can stop them, but because of its high energy output, the Muramasa Blaster cannot be used for an extended period of time and was thus designed to be useful even unpowered. Otherwise, the X-3 is effectively identical to its predecessors.