Attempting to Take Over the Eggman Empire
At some point in the recent past, Metal Sonic transformed into this form in an attempt to take over the Eggman Empire. After betraying Eggman and disguising himself as the doctor, he eventually clashed with Sonic in the Egg Emperor mech. Not only did he lose in this battle, but when he was found out to be a fake, he was defeated by Team Sonic and turned back into normal. Eggman would then repair Metal Sonic and remove its rebelliousness from its coding. (StH: #1, #7)
Upgraded to the Greatest Weapon
Eggman decided to upgrade a now obedient Metal Sonic into his Neo Metal Sonic form once again to be used as his greatest weapon in the final battle during the war between the Eggman Empire and the Resistance, but the upgrade wasn't completed until after Eggman had already lost and went missing. As Neo Metal Sonic was given Eggman's Bio-Data, genius, drive, and vision, he decided that he would use his persona to ensure his reign remained unbroken and then find the doctor so that he could hand the control of the world over to him. (StH: #7)
Approximately a month after the end of the war between the Eggman Empire and the Resistance, Neo Metal Sonic, disguised as Dr. Eggman, made his first move by taking control of the Eggman Empire's wayward Badnik hordes that had scattered everywhere and directing them into attacking various villages across the globe. As his first "trial" for Sonic, whom he kept a close eye on via a Flapper, Neo Metal Sonic had a Badnik battalion attack a village in order to draw Sonic into a fight. When Sonic met up with Tails there and the two emerged victorious, Neo Metal Sonic had another Badnik battalion attack a nearby village to lure Sonic into an ambush. He also made sure Sonic's success reached the Resistance so that the group's core staff member, Amy Rose, would join Sonic on the battlefield and get crushed with him. After both hedgehogs ended up defeating the Badniks, Neo Metal Sonic noticed that Sonic was deviating from his projected path, much to his annoyance. However, when Orbot reported that Sonic was heading for a village where Rough and Tumble resided, Neo Metal Sonic had hopes that the skunk brothers could finish Sonic for him. Although the skunk brothers failed, Neo Metal Sonic learned from surveillance that Knuckles the Echidna was still not protecting Angel Island. This meant the Master Emerald was there for the taking, which Neo Metal Sonic realized would accelerate his master plan significantly. (StH: #1, #2, #3, #4)
While following his forces via surveillance from a Flapper, Neo Metal Sonic caught sight of Sonic and the Chaotix just before his Flapper got taken out by Charmy Bee. This made Neo Metal Sonic suspect either that his forces had found another settlement, or that Sonic had figured him out. Regardless, once Orbot reported that the Egg Fleet was getting into position, Neo Metal Sonic decided to join up with it in order to carry out the next phase of his plan. (StH: #5, #6)
Onboard his flagship, Neo Metal Sonic got a surprise visit from Sonic when he infiltrated his ship. Neo Metal Sonic tried fooling Sonic with his Eggman disguise, but Sonic saw through it because he met Eggman earlier. Neo Metal Sonic thus decided to drop his disguise and let Sonic in on his motivations for taking over for Eggman, whose whereabouts he intended to get from him. This prompted Sonic to try and defeat Neo Metal Sonic, but the robot soon gained the upper hand by copying his bio-data. Eventually, Sonic tried to escape, which Neo Metal Sonic tried to prevent with the aid of his Badniks and his ship's artillery, which Sonic destroyed in the process. In the end, Sonic escaped with Tails and the Tornado's aid. Having nothing left to fight the escaping duo with, Neo Metal Sonic allowed them to flee, and resumed his plan with the knowledge that Sonic was unaware of what he was up to. Soon after, Neo Metal Sonic and the Egg Fleet reached the airspace surrounding Angel Island. (StH: #7)
Neo Metal Sonic shares some distinctive traits with his normal form, such as black eyes with red irises, similar torso with a rocket engine, and the primary blue color with red shoes, but he has a number of differences too. His head has five long quills as opposed to his regular three, with white stripes and markings around his eyes, similar to that of Shadow's. The yellow color in his ears has been replaced with red and his nose is now black.
He also possesses more pronounced body armor, with black and curved shoulder plates, larger gauntlets and leg armor with pointy knee caps that have white outlines, a plate covering his pelvis and elf-like shoes. He also sports a spiky belt with a black cape that protrudes out of the back of his waist.
Neo Metal Sonic is a very powerful transformation with seemingly limitless potential. On his own, Neo Metal Sonic was able to fight Sonic to a standstill, and eventually overpower him.
Neo Metal Sonic is able to scan the life data of other life forms, allowing him to copy and replicate others' skills and abilities flawlessly. On his own, he is also surprisingly durable, being able to take a barrage of attack from Sonic and emerge from them almost undamaged. He also possesses limitless stamina and the ability to fly via the rocket engine on his back.
Neo Metal Sonic also has the power to shapeshift, allowing him to change his appearance and body structure. This allows him not only to perfectly imitate the appearance of organic creatures, but also the appearance of robots as well
- Neo Metal Sonic is based on the transformation of the same name that debuted in the video game, Sonic Heroes.