- You may be looking for the article on the original Metal Sonic.
Metal Sonic v3.0, also known as "Dr. Eggman's Undying, Heartless Weapon of Misery and Despair", was a line of Metal Sonic robots created by Dr. Eggman. Modeled after Dr. Ivo Robotnik's original Metal Sonic, this Badnik lacked the Free Will Algorithm gained by its predecessor and proved to be unwaveringly loyal to Dr. Eggman as well as effective against Sonic the Hedgehog to an extent. Numerous versions of Metal Sonic have been produced by Eggman, as successive units are destroyed in battle against Sonic and other enemies. Nevertheless, each successive model became more dangerous to confront, and its threat potential only increased after being joined by other similar Badniks as part of the Metal Series. Though most models have been silent and emotionless, the eighth variation was equipped with more free will and speech abilities.
First Model (v3.0)
When the Freedom Fighters and Shadow the Hedgehog found a lost military base from before the Xorda attack, Dr. Eggman constructed Metal Sonic and sent him to investigate, as well as engage Sonic in combat. (StH: #146)
Sonic, Metal Sonic and Shadow all got into a three-way brawl upon meeting up, with the latter two eventually teaming up against the blue blur. When the three were separated, however, Metal Sonic found himself conversing with the base's caretaker, Isaac, about the history of the instillation and Mobius itself. (StH: #147, #148)
When the three started fighting again, they stumbled upon an ancient missile that Isaac was about to launch. The missile was stopped by Shadow and Sonic, and the new Metal Sonic was defeated and destroyed. (StH: #148, #149)
Second Model (v3.1)
Following this encounter, Shadow located the facility on Prison Island where Professor Gerald Robotnik had finished creating him and was last seen alive. There, a replacement model of the destroyed Metal Sonic suprised and engaged Shadow in combat. The two were rendered unconscious when Metal Sonic fired a super charged weapon that caused a major explosion nearby. Eggman's "daughter" Mecha retrieved the damaged Metal Sonic and brought him back for repairs, while also bringing Shadow with her. (StH: #157)
Some time later, Metal Sonic soon captured Sonic and brought him to Dr. Eggman, who used a device to control Sonic's body. When Metal Sonic went into some sort of stasis, Snively, frustrated with Eggman's childlike methods of defeating Sonic, decided it would be a good time to betray his uncle once again. When he attempted to reprogram Metal Sonic to work for him however, he found that it was spying on him. Eggman revealed that he knew of Snively's treacherous ways, and programmed Metal Sonic, along with every other robot, to monitor Snively in case he decided to back stab him once again. When Knuckles destroyed the device in Sonic's ear, Eggman and Metal Sonic attacked Knothole Village, but Metal Sonic was easily destroyed by Sonic, Tails, and Knuckles. (FCS: #1)
Third Model (v3.2)
A new model was produced and used to attack Freedom HQ. Unlike previous models, this Metal Sonic allowed Dr. Eggman to speak through it via radio transmission. When Scourge the Hedgehog explained to Eggman that he and the Suppression Squad had taken over Freedom HQ, Eggman simply had the new Metal Sonic attack him. Sonic arrived on the scene shortly afterwards, but Scourge decided he preferred to fight alone and not get help from Sonic, despite having little success against the robot. Metal Sonic then proceeded to attack both Scourge and Sonic, and reinforcements arrived moments later in the form of Metal Scourge. (StH: #191)
While holding the upper hand against their organic counterparts, both Metal Sonic and Metal Scourge were quickly destroyed by the Suppression Squad. Their parts were salvaged, however, and used by Sir Charles Hedgehog to reconstruct Shard. (StH: #192, #238)
Fourth Model (v3.3)
Shortly after the destruction of both Metal Sonic and Metal Scourge by the Suppression Squad, Eggman created a new Metal Sonic model, this time using the newer SXSU-401 engine instead of the typical STH-25, allowing the robot to transport to any other dimension to pursue Sonic. Metal Sonic then left for Moebius against his creator's will to find and attack Sonic and the others in Castle Acorn. Sonic later made an offer for Metal Sonic to help him take out Scourge first, instead of attacking everyone else, and the robot nonchalantly agreed. Scourge didn't give up, however, and rushed to the throne room, followed by Sonic and Shadow. Scourge then turned the tables on everyone by revealing that he had placed Anarchy Beryl in his throne. This managed to transform Scourge into a stronger form; Super Scourge. (StH: #195)
Metal Sonic was temporarily defeated by Super Scourge along with the others and then tried to attack Sonic again when he deduced that defeating Scourge was no longer an option. It was later transported to another location along with Shadow when he tried to override Metal's teleporter engine with Chaos Control. Arriving in an alternate universe, Metal Sonic was employed by that reality's version of Dr. Robotnik to attack everyone, but was once again transported to a different reality by Shadow. (StH: #196, SX: #40)
Metal Sonic and Shadow then ended up in the Sol Zone, floating above an ocean. Shadow tried to convince Metal Sonic to no longer obey Dr. Eggman, but Metal Sonic completely ignored Shadow's request and kicked him into the water before flying off to look for the zone's version of Eggman. Furious that he could not locate that zone's Robotnik, Metal Sonic began attacking Southern Island. Shadow, Blaze and Marine showed up shortly to witness the destruction Metal Sonic had caused. Blaze furiously attacked Metal Sonic, but the machine simply used his powers to reverse Blaze's attack. Neither Shadow or Marine could take down Metal Sonic. However, Shadow tried once again to convince Metal Sonic to work with him, but Metal Sonic simply pointed out they each had different goals, and his was to serve Dr. Eggman. Thus, Blaze set fire to Metal Sonic, and Shadow charged at him. The robot flew towards the Ocean Tornado, and Marine destroyed him with the ship's cannon. (SU: #1)
Fifth Model (v3.4)The next Metal Sonic model appeared during Sonic and Sally's attempt to thwart Dr. Eggman's Operation: Clean Sweep aboard the Death Egg Mark 2. Soon after Eggman revealed his new world Roboticizer and a simulation of it's devastating effects on Mobius, Sonic moved to attack the doctor when a new Metal Sonic swooped down from behind and charged him. Ranting on the latest model, Sonic battled his robotic counterpart as it worked in tandem with a damaged Silver Sonic v3.0 from an earlier fight. (StH: #230)
As the fight went on, it seemed Metal Sonic and his giant silver brethren would be victorious. A light then flashed from the Roboticizer as it activated, however the device exploded due to a malfunction and destroyed the room, heavily damaging the Death Egg. Already being a robot, Metal Sonic was incompatible to the Roboticization process just like other mechanics, and it blew up into a robotic mess with its head severed. (StH: #230)
Sixth Model (v3.5)
This unit was built after Operation: Clean Sweep and appeared alongside the upgraded Mecha Sally when Dr. Eggman attempted to assassinate Elias Acorn and his family while relocating from New Mobotropolis to Feral Forest, and at first focused on Sonic as it's primary target while proving to be too much for the deroboticized Bunnie. As the robots battled with the convoy's escort, Dr. Eggman ordered Metal Sonic to latch onto the Mobo-Cruiser carrying the Acorn family and detonate. Antoine removed Metal Sonic from the vehicle in time, however, and was the only one caught in the robot's explosion, which left him comatose. (StH: #234, #235)
Seventh Model (v3.6)
Dr. Eggman unveiled the seventh incarnation of Metal Sonic v3.0 to his Dark Egg Legion Grandmasters along with the rest of the Metal Series for the purpose of serving as the doctor's new enforcers as a result of Snively's betrayal. It accompanied Mecha Sally in joining the Eggman Empire's attack on Central City in an effort to find Snively. During the battle, Metal Sonic and Mecha Sally were able to take E-123 Omega by surprise and attacked him using their laser cannons. As Snively attempted to escape again, Mecha Sally and Metal Sonic effortlessly destroyed the G.U.N. fighters sent out to bring down Snively's craft before returning to the Egg 'Stache Flyer to continue the chase. It was then dispatched along with Metal Tails and Metal Amy as Team Metal in New Mobotropolis with assistance from Tails Doll in an attempt to get rid of Team Freedom, but as it was about to engage Heavy and Bomb, Metal Sonic was attacked by Shard, the original Metal Sonic, who then proceeded to destroy it. (SU: #37, #38, StH: #240)
Eighth Model (v3.7)
Dr. Eggman deployed the eighth incarnation of Metal Sonic to destroy Shard, who had defeated his predecessor. Equipped with Eggman's last Power Gem, memories of all the defeats of his predecessors, and greater free will, it was initially opposed to the idea of going after Shard as opposed to Sonic. However, having learned from his previous attempts, Eggman had installed a soft-reboot defiance kill-switch, which quickly halted any inclinations of disobedience. Pleased with the device's success, Eggman lamented that he had been unable to fit Shard, Gamma, or Omega with such devices as well, not to mention the impossibility of using one on Snively. Metal Sonic soon arrived in New Mobotropolis, arriving so quickly and disrupting NICOLE's systems by some means that left her unable to prevent its entry. It proceeded to Tommy Turtle Memorial Hospital, where it located Antoine and was about to finish what v3.5 had started when Shard arrived to confront it. Fortunately, Shard was able to goad Metal Sonic into fighting elsewhere and leaving the helpless Antoine where it had found him. The pair flew to the Great Wastes, which Metal Sonic chose as their battle site because it was "proof of robotic superiority" given the success of Mecha Sonic against the Freedom Fighters there in the past. Shard pointed out the irony that despite the apparent "inferiority" of organic lifeforms, some robots strove to become more like them, and pointed out Metal Sonic's own increased personality. (SU: #50)
Metal Sonic claimed that it had been improved upon to the point of perfection, and to which Shard demurred, citing his own efforts to help the people of the Republic of Acorn gain a more positive impression of robots. Metal Sonic expressed its utter lack of care for Shard's attempts or his own actions, and the pair quickly engaged each other in battle. The battle was intense, each unit deploying their individual methods of attack and defense, but Metal Sonic soon gained the upper hand. Using memories of its predecessors' battles with various Mobians, it jammed Shard's laser cannon arm with a rock, deflected his Spin-Dash before responding with its own, and vaporized the rock when Shard launched it from his cannon. Held in Metal Sonic's grip, Shard attempted to reason with it, telling him that he could become more than just a weapon, reminding Metal Sonic of Shadow's efforts to convince v3.3 of the same thing. However, the kill switch activated again, and Metal Sonic prepared to terminate Shard before moving on to New Mobotropolis. Determined to stop it, Shard retaliated with his adaptive arm, using its cannon feature again before turning it into a drill in an attempt to finish Metal Sonic off. Metal Sonic severed the limb with its shield, but Shard was determined to destroy it even when warned of the danger to himself. He went after the Power Gem core, and Metal Sonic realized the vulnerability of the feature and caused it to explode, consuming itself and badly damaging Shard. (SU: #50)
Ninth Model (v3.8)
Dr. Eggman created the ninth incarnation from the remains of the eighth incarnation after its battle with Shard. Retaining the previous version's memories, he reported Shard's destruction-or so it seemed-and the loss of his Power Gem core. He then prepared to go after New Mobotropolis, but was informed that Tails Doll would handle that; he was also informed that, despite his desire to do so, he would not be sent after Sonic. Eggman deployed Metal Sonic to the Interdimensional Gateway to meet his new partner, whom he claimed Metal Sonic would like due to his status as a "base villain" like the robot itself. Metal Sonic accepted the assignment, and was informed by Eggman that it was his "undying, heartless weapon of misery and despair." Deciding that this was acceptable, it prepared to leave as Eggman, Orbot, Cubot and Mecha Sally looked on (SU: #50).
After the world had once again been reset by the Genesis Wave, Metal Sonic was paired with Bass, the newest assistant of Eggman's new partner, Dr. Wily, and sent to kidnap Tails. The two henchmen swiftly overwhelmed the two-tailed fox and took his unconscious body back to the Doctors. Following this, Metal Sonic went to Mega City to attack Mega Man. He struck the blue bomber from behind and then fled through a warp ring to Mobius, where the real Sonic was chasing Megaman's double, Copybot, in Green Hill Zone. Following instructions from the Doctors, the two evil doubles lured their counterparts to each other's location as part of a ploy to trick the two blue heroes into fighting each other, which was successful. His objective complete, Metal Sonic sped off to await further orders (MM: #24, SU: #51).
When the battle between Sonic and Mega Man unexpectedly moved to Mega City in Mega Man's world, Wily guessed that it was the work of Dr. Light, Mega Man's creator. Worried that Light would be a threat to their plans, the two doctors sent Metal Sonic and Bass to deal with him (STH: #248).
In terms of personality, Metal Sonic has displayed little to nothing in the vast majority of its incarnations. Single-minded and unquestioning loyalty to Eggman was its function, as per its creator's design; having experienced previous failures with free will programming, Eggman didn't want to chance his prized creation turning against him. Despite attempts by Shadow to reason with one model, all versions of Metal Sonic v3.0 have remained devoutly loyal to Eggman. However, it is notable that the same model was also persuaded to join Sonic, Shadow, Amy Rose, Robert O'Hedge, and Silver the Hedgehog against Scourge.
Metal Sonic is often viewed as cold and merciless, even mindless, and the majority of models have been silent during battle. For some, speech was not even an option: the fifth, sixth, and seventh models were voiceless, and the third model merely served as a radio mouthpiece for Eggman. The eighth model was equipped with a voice and more developed personality programming, which expressed cold outrage at the losses of previous models and and a single-minded desire to destroy Sonic. It also briefly expressed rebellious tendencies at the idea of being ordered to attack another enemy, but Eggman's safeguards quickly rendered it docile.
Being a robotic clone of Sonic, Metal Sonic has access to many of Sonic's powers and abilities thanks to his equipment. Including the rocket pack in his back, that allows him to run at speeds possibly surpassing those of even Sonic himself. Metal's speed and power vary from the different models, the third one proving too much for Sonic or Scourge. In addition to Sonic's abilities, Metal has numerous other capabilities. He can fly by utilizing the rocket pack on his back along with impressive strength and moderately strong armor.
Over time, the newer line of Metals began to get extra features and upgrades. The third Metal Sonic created by Dr. Eggman, had some sort of energy cannon that it fired from out of the front air intake of its engine housing where his stomach would be. The fourth Metal Sonic had the same cannon design which it used on Shadow and was also able to teleport due to the SXSU-401 engine. The sixth and eighth Metal Sonics were equipped with a self-destruct mechanism, and it is likely that the other models also possess this ability. The seventh version of Metal Sonic can do a combo attack with Mecha Sally using a laser installed in its back.
After the seventh models battle with Shard, Eggman determined that his decision to leave out a free will algorithm in Metal Sonic, to prevent rebellion, made it weaker then the original. To correct his mistake he installed his last Power Gem into the eighth model of Metal Sonic, containing the free will algorithm and all the battle data of the previous models battles, so it could think during a battle and learn from its mistakes. He also installed a soft-reboot defiance kill-switch to prevent it from rebelling against him like his predecessor. Unfortunately, the Power Gem was destroyed in Metal Sonic's subsequent battle with Shard, but the ninth model, rebuilt from the parts of the eighth, retained its free will and memories even without the power gem.
- Interestingly, another Metal Sonic was seen being built in the background when Espio was sneaking through Eggman's lab. It can be assumed that this is the Metal Sonic later used to attack Scourge at Freedom HQ. (StH: #174, #191)
- It's possible that the inclusion of Eggman being able to talk through the third model via voice communication is a reference to Metal Sonic's appearence in the PSP game Sonic Rivals 2, because Eggman actually used Metal Sonic to talk to Shadow in the game.
- The fourth Metal Sonic spoke in a manner similar to that of HK-47, where he states what type of thing he's going to say before he says it. For example: he says "Explanation: Super form ensures 0% success rate." in StH: #196.
- The fifth Metal Sonic is strikingly similar to the second model as both were seen in action for only a short time and physical details.
- Metal Sonic's first engine is named the STH-25, after the first Sonic the Hedgehog issue he appeared in.
- Metal Sonic's newest engine, the SXSU-401, is named after the first issue he appeared in a Sonic X comic and Sonic Universe respectively.
- SX__-40_ = Sonic X #40
- __SU-__1 = Sonic Universe #1
- This Metal Sonic's designation as v3.0 was confirmed by writer Ian Flynn of the Archie Sonic the Hedgehog comic blog. 
- v3.6 is the only model that did not face Sonic and the only version to be part of the Metal Series. v3.3 and 3.7 onward are the only models capable of speaking.
- Before the introduction of 3.7, Ian Flynn purposefully made Metal Sonic v3.0 a machine without personality, being of the opinion that it makes him "more creepy" and that it would be redundant to portray him as obsessed with beating Sonic as his game counterpart is, given that several characters-notably Shadow-already exist with that agenda in the comic.
- The large number of Metal Sonic v3.0 versions-some of them in rapid succession-is a sore spot with some fans, who feel that the character isn't as impressive as he should be in terms of ability.