When performing Omega Arm, Omega releases his teammates from his grip (due to holding them for the move's initial attacks) and stands in one place while spinning his robotic torso around clockwise. While doing so, Omega unleashes a full-force weapon barrage from his built-in arm cannons, which he transforms according to the weapon he uses. This results in a spiral-like wave of artillery that damages anything caught within its radius.
To perform this technique in gameplay, the player must have Team Dark in Power Formation, with Omega as the leader, and must have performed the Spinning Back punch. Right after using the Spinning Back punch, the player then has to press // to use the Omega Arm.
By collecting red Power Cores during gameplay, the player can increase the power, nature and radius of the Omega Arm. The levels of power are as follows:
Level 1: Omega reconfigures his claws into Gatling Machine Guns and fires a hail of bullets in a circular radius around him.
Level 2: Omega reconfigures his claws into Flamethrowers, spraying flames in a circular radius around him. Attack radius is increased about a couple of meters and the resulting damage dealt is doubled.
Level 3: Omega reconfigures his claws into Missile Launchers and unleashes a barrage of drill-like missiles in a wide circular arc that create explosions upon contact with nearby enemies or obstacles. Attack radius and damage is at maximum. The missiles fire in a slight upward angle so they may not hit ground enemies from a far distance.