The X-4 acts as an middle-close range assault unit and as support for the X-1 by providing cover firings. Attached to an armed module which armed with 2 large beam sabers, machine guns and grenade launchers, she is capable of massacre of a small company of enemies. One important thing is that this unit also serves as an ECM unit to conduct electronic warfare and jamming communications to 'cripple' the enemies in major battles.
Most of the time, the X-4 is paired with the X-1 to penetrate enemies in the front line and due to it's sizes, the X-4 has limited spaces for actions unless she detaches from the module. Nevertheless, she can still uses a variety of hand-wield arsenals to provide fire supports for the X-1.