Sigma is an evil Reploid from the future of Earth 20XX and an adversary to X and his various allies. After forcing Dr. Ivo "Eggman" Robotnik to construct a new body for him, he began going by the name Sigma-1. Later, after plugging himself into a massive new body that was fused with the Lost Hex, he became known as Sigma-2. After shedding that form and gaining power beyond even that granted by a typical Super Transformation, he became Sigma-3.
A Fallen Hero
Sigma was once the leader of a force of Reploids designed to halt rampaging Mavericks, Reploids who had turned against humanity due to a virus. His efforts led him to a battle with Zero, and both of them were exposed to the virus during the confrontation. Sigma was eventually corrupted by the virus, and began to see humanity as oppressors who were holding the Reploids back from their full potential. This led him to rebel against humanity and become the leader of the Mavericks, which led to war between himself and heroic Reploids such as the reformed Zero and X, the original Reploid. (MMX)
Sigma later traveled to the universe that was home to Sonic's World via one of the Genesis Portals, and infiltrated Dr. Ivo "Eggman" Robotnik's base on the Lost Hex. He did so after observing this world for some time, but was forced to accelerate his departure when X and the Maverick Hunters attacked his fortress. Noting that Eggman had set the stage for him through his treatment of the Zeti, he mocked the arriving X and informed him that he would soon be master of more than one world. Reduced to pure computer data, he took control of Orbot and shattered the Cacophonic Conch that Eggman used to control the Deadly Six. The Maverick leader and his Zeti allies then forced Eggman to build Sigma a new body, transforming him into Sigma-1. Much to Eggman's dismay, he was then forced to remain a part of Sigma's plans, and reunited with his former ally turned enemy Dr. Albert W. Wily, whom Sigma brought through Genesis Portal to Mobius. Forcing the two doctors to convert the Lost Hex's Badnik assembling plant into a Mechaniloid factory, he also outfitted the Deadly Six with armor to augment their abilities but which included a trap for the alien villains. Zavok briefly attempted to use his enhanced abilities to take control of Sigma, only for he and his teammates to fall subject to mind control devices hidden in their new armor. Having been forced to play this card early, Sigma ordered the doctors to begin work on the Unity Engines, and then deployed the Deadly Six-at their suggestion-to capture Sonic the Hedgehog and Mega Man. (SU: #76)
Wily and Eggman soon converted the two heroes into two more commanders-the Deadly Six making a total of eight-for Sigma's forces: Sonic Man and M'egga Man. He promptly sent the two Roboticized Masters to Mega City and Mobotropolis, respectively, in order to place a Unity Engine in each location. To Sigma's delight, they managed to set up their engines despite some resistance, and soon the Master Engine began feeding the power of the fusing worlds into him. However, when his two new commanders turned on each other, Sigma realized that he had been betrayed by Eggman and Wily, and sent several of the Zeti to hunt them down. The pair managed to escape with aid from Xander Payne, but Sigma remained confident in victory, as he had already rebuilt or revived an army of Mechaniloids to do his bidding. While this force-under the Deadly Six-engaged the arriving heroes in the Sky Patrol, Sigma also set about reviving various defeated Mavericks by combining his new power with that of the Genesis Portals. In his mad ambition, which saw him willing to destroy his own world for more power, Sigma even reached into the future to bring forth Mavericks who had not yet served under him. He noted that these Mavericks weren't perfect Time-Clones, as their personalities were not intact, but was content with their loyalty to him. (SB: #8, #9, StH: #273; MM: #50; SU: #77)
The heroes succeeded in defeating Sigma's Mechaniloids and the Deadly Six, but Sigma's new army had been completed in time. Worse yet for the heroes, Sigma had also crafted a massive new body-known as Sigma-2-for himself befitting his new power, which he entered before emerging from the Lost Hex to tower over his minions and foes alike. As his Mavericks menaced the outnumbered and weary heroes, Sigma contemplated the power he had received from the dying Unified World, and thrilled at the power he anticipated receiving from various worlds he intended to conquer. Seeing the heroes barely able to stand, he called back most of his Mavericks, opening an array of new Genesis Portals and dispatching them with Unity Engines to various worlds. He left a handful behind to finish off the heroes, and then turned his attention towards seeking out other worlds that he could harvest for power. However, his foes were unexpectedly joined by heroes from the Street Fighter Zone, who dispatched the remaining Mavericks. The heroes then prepared to pursue Sigma's forces to various worlds in small teams, while also gathering the seven Chaos Emeralds as a backup plan. (StH: #274; MM: #51)
Realizing what the heroes were trying to do, Sigma attacked and destroyed the Sky Patrol. However, the heroes and their new allies from various worlds soon launched an attack on him and his Mechaniloid and Maverick defenders. His massive body was destroyed as a result, but proved to be a mere cocoon for his ultimate form, Sigma-3. Sigma would face Super Sonic and Super Mega Man in a climactic battle to decide the fate of the Multiverse. So great was the power he had obtained through his Unity Engines that even these heroes proved no match for him, until Eggman and Wily cut him off from the Master Engine's powers. They then defeated him, but his use of the Genesis Portals threatened to tear reality apart. His reign of terror was halted-and ultimately undone-by Xander Payne, who used a Genesis Portal to destroy Sigma's virus form before it ever beamed back in time and took control of Orbot. (SB: #10; SU: #77; StH: #275; MM: #52)
Sigma is a dangerous megalomaniac, utterly convinced of the superiority of Reploids over Humans and other intelligences. He moreover considers himself superior to other beings, and takes a sadistic pleasure from forcing other beings to do his bidding. Like Dr. Eggman before the Super Genesis Wave, his desire for power is such that he is willing to tamper with the very fabric of reality, both through utilizing the Genesis Portals and creating the Unity Engines. Sigma is also a master manipulator, maneuvering heroes and villains alike to his own ends, and thinks big when formulating a plan. His greatest weakness is his massive ego, which leads him to believe he is invincible despite his past defeats.
As an intelligent computer virus, Sigma is capable of possessing machinery such as Orbot. While such bodies are susceptible to the technology controlling powers of the Zeti, his programming is apparently beyond their command. How he gained command of the Genesis Portals is unknown, but he is shown to have great control over them, being able to open new portals at will. In his Sigma-1 form he also gained the ability to use the power of the Genesis Portals and Unity Engines to clone various minions. His powers were heightened in his Sigma-2 body, which possessed immense strength and the ability to open multiple Genesis Portals at will. After shedding this body to become Sigma-3, his power became even greater, such that he was able to take on both Super Sonic and Super Mega Man with little effort.
Sigma loosely resembles a tall, muscular human man with a bald head and a cleft chin, but is easily recognizable as a robot due to his blue optic sensors, which have purple markings around them. A circular red protrusion is visible on his forehead, and in place of ears he has circular metal forms on the sides of his head. The rest of his body is visibly metallic, with green armor on the torso and blue on the forearms and white hands. His thighs are covered with black material, while around his knees are rings of spikes matching those on his wrists. A red belt encircles his waist with a metallic plate descending from the front of it, and his lower legs and feet resemble brown boots with yellow bottoms and metal bands linking the sides of his ankle on either foot. Sigma also favors a high-collared cape with a red side-usually turned outwards-and a purple side-turned inwards-decorated with gray armor on the shoulders.
Prior to departing for Sonic's World, Sigma appeared in holographic form as a gigantic, purple-tinged version of his usual head. During his alliance with the Deadly Six, Sigma's design was modified in a number of ways. His shoulder armor on the outside of the cape gained black accents on the gray, and he donned a new cape that retained the purple interior but changed its exterior to black. His torso, forearm, and lower leg armor became red, while his feet became green and black. Instead of his old belt, Sigma donned a new one with an emblem buckle mixing the insignias of Drs. Wily and Eggman: a Skull with what looked like Eggman's mustache coming out from behind it.
Sigma later adopted a gigantic body, many times the size of his normal form and larger than even the Sky Patrol. The torso of this form had a stylized design resembling the head of Zavok, leader of the Deadly Six. This form lacked a lower body, and was instead fused into the Lost Hex. His final form was closer in size to his original body with white and black armor.
- Sigma originates from the Mega Man franchise's Mega Man X sub-series, of which he is the main antagonist. Although X and his allies destroy him at the end of almost every game, his spirit continuously endures to scheme another day.
- Sigma's melee weapon of choice in his original appearance--an energy sword, like Zero's--closely resembles (and functions like) a lightsaber from Star Wars.