Rei's Abilities

[Megamerge] — As long as he is within a 1 meter radius of the Model O, he is able to don it's powers and it's weapons.  When Megamerged, Rei's appearance becomes nearly identical to that of Omega's albeit, his scarf is still apparent along with a triangular gem on his chest, as well as, he can utilize the O-Saber and the O-Buster, a 1 meter long energy saber and a chargeable energy gun.

[Overdrive] — While Megamerged, Rei can activate Overdrive, an ability that allows him to massively increase the amount of power in all of his strikes, as well as, perform other feats that he wasn't initially capable of while Megamerged. However, it's usage will strain him greatly with overuse leading to death.

[Machine Out] — While within the range of megamerging, Rei can disable any and all machinery in a 500 meter radius, though this will give him a massive headache, which prevents it from being used consecutively.

[Cyber Passage] — While within the range of megamerging, Rei can transport himself and the Model O into Cyberspace. This will, however, prevent him from seeing those outside of Cyberspace and he cannot leave Cyberspace until at least 10 seconds have passed.

[Absolute Overdrive] — During Overdrive, if Rei enters his Berserk state, this form will automatically activate. Absolute Overdrive increases the output of Overdrive immensely while at the same time reducing the intial risks but due to it's lack of control, it tends to not get activated. It changes the appearance of Rei, changing his color scheme and changing his armor's shape.

[Berserker] — Due to the Model O's Reploid Soul's personality programming seemingly starting to merge with Rei's own, his personality took a turn for the worst. Due to this, he can sometimes enter a Berserk state, where he will fly into unbridled rage and attempt to attack, and possibly kill, anyone or anything that is around him.