Sigma (Mega Man X)

"Bwah ha ha ha. Your efforts are futile... I will never be defeated! As long as Mavericks exist... As long as evil exists in the minds of humans... I'll come back again and again! X, Zero... I'll pursue you to the end of the world! Bwah ha ha ha! Farewell! FOR NOW!! Bwah ha ha!"

- Sigma "Gha ha ha ha ha...! Isn't it painful to have to watch while others suffer? You can put up with your own pain......but can't bear to see others, especially Zero, harmed, can you? I'm taking Zero, the one most important to you... to the underworld! Goodbye, X... Gha ha ha ha!"

- Sigma

Sigma is the supreme commander of the Mavericks and the main antagonist in the Mega Man X video game series, serving as the final boss for most games of the series (except for X8 and Command Mission).

History
Created by Dr. Cain, Sigma was considered the finest of the Reploids (having been the first made) and was the first leader of the Maverick Hunters - peace-keeping Reploids who defend humans against their renegade robot counterparts. Although he was once honorable, Sigma unexpectedly goes Maverick in the beginning of Mega Man X and rebels against humankind (the reason for this was that he was infected by the Maverick Virus, which he received from Zero). He defects to the Mavericks and assumes the role of their leader. Under Sigma's command, the Mavericks grow into a legion dedicated to the extermination of the human race. Sigma instigates many of the destructive Maverick Wars, with the Maverick Hunters existing to crush Sigma and his minions.

Sigma appears as a bulky, bald humanoid in most of his forms; his most pronounced feature is a crystal on his forehead, and two parallel scars running through his eyes. He often produces a second form after his initial defeat in a game, which frequently has the head (or the crystal on it) as a weak point. Although he has been destroyed countless times, Sigma's programming always survives and builds himself a new form, ready to menace the world once again. It is implied that he grows more insidious and vengeful with each transformation, with each successive plan becoming more and more desperate and aggressive.

Mega Man X
Sigma starts his revolt, with many former Maverick Hunters joining him out of loyalty. X and Zero are then forced to fight the Maverick forces, with X eventually reaching Sigma on his palace. Sigma laments X's decision to side with humanity, deciding to test him by by sending his pet robot Velguarder. After X destroys Velguarder, Sigma is pleased with X's progress and decides to confront him personally.

On the first phase of the fight, Sigma will attempt to slash X with it's sword, defend incoming attacks and jump around the walls. In the remake Maverick Hunter X he will also shoot beams from his eyes. This form is weak to the Electric Spark, but you can also one-shot him with the Hadouken if you're fast enough. Upon exploding his head will float and attach to a giant body called Wolf Sigma. In this form it will attack by shooting fire and lightning. The best strategy is to jump into one of his hands to reach his head, which is his weak spot, and use his weakness, the Rolling Shield.

After the credits roll, Sigma appears on a monitor and promises to come back in a new body to get his revenge.

Mega Man X2
Sigma returns and orders the X-Hunters to retrieve Zero's parts, which he planned to reprogram to serve him. His plan fails, however, as X is able to retrieve the parts first, which Dr. Cain works on reassembling while X assaults the X-Hunters base. After X defeats the X-Hunters, Sigma confronts him, pitting him against a fake copy of Zero, which the real Zero promptly blasts. Sigma the retreats to a lower floor, where X confronts him.

On his first form, Sigma uses his claws to attack, as well as teleporting around the arena and shooting electric sparks which home onto X. This form is weak to the Sonic Slicer. Upon exploding, Sigma appears in his true, virus form, appearing as a transparent wireframe, his attacks involving spitting out minor enemies found throughout the game as well as shooting a beam from his mouth. This form is weak to the Strike Chain.

Again defeated, Sigma promises he will come back, but also tells he doesn't understand why Zero sided with X, as he points out he is "the last of the doctor's creations".

Mega Man Xtreme
Sigma uses the hacker Techno to hack into the main computer of the Maverick Hunter base, also sending Zain and Geemel to invade it as X entered it to combat Techno's viruses. Sigma's forms in this game are identical to those of the first game, even the weaknesses.

Mega Man X3
When the scientist Dr. Doppler develops a vaccine to counter the Sigma Virus, Sigma immediately takes action and brainwashes Doppler, using him to stage a new revolt on his utopic Doppler Town. After X defeats Doppler, he comes to his senses and reveals than not only Sigma brainwashed him, but also that he made a new powerful battle body for Sigma, urging X to go after him. When X finds Sigma, he tell that it was very easy to corrupt Doppler, and his plan would have succeeded had X not interfered, so he once again challenges X to fight.

On his first form, Sigma uses a shield to protect himself while shooting fireballs, after which he will jump to the other side of the screen, stopping midair to shoot more fireballs. When his energy is halved, he will also throw his shield. His weakness is the Spinning Blade. On his second form, Sigma emerges in a giant body called Kaiser Sigma. He will shoot homing missiles and drones, as well as shooting a huge beam of light. This form is very difficult, due to his small head (his weak point) being very hard to hit, as well as his massive size, which makes it hard to dodge his attacks and maneuver around the room.

Upon being destroyed, Sigma once again appears in his viral form, pursuing X in an attempt to possess his body. He manges to corner X, but Dr. Doppler appears and draws Sigma within his own body, which was full of his anti-virus, which makes Sigma's code to start to disappear.

Mega Man Xtreme 2
Sigma will only appear in the Xtreme mode, where he reveals he was behind the Erasure Incident the whole time, though he thanks X for disposing of Berkana, as she went too far. His first form is identical to his first form in X2, but his second form is totally new, appearing in a large body with a lion on his chest. After he is defeated all Reploid souls return to their bodies.

Mega Man X4
Sometime after his last defeat, a new group of Maverick Hunters called Repliforce is created, in order to assist the Hunters. Sigma, knowing they could pose a significant threat, enacts a plan to pit the Maverick Hunters against the Repliforce. He initially appears attempting to convince the General, leader of Repliforce, to wage war against the Hunters, with the pretense that they would soon turn on the Repliforce, but General quickly dismisses him. Sigma then puts his plan B in action, staging the destruction of the floating city of Sky Lagoon, convincing the Maverick Hunter Magma Dragoon to take down the power core of the city while a mechaniloid under Repliforce's control called Eregion attacks the place. Both the Maverick Hunters and Repliforce arrive at the place, but as the city plummets to the ground the Hunters blame Repliforce for the attack, as the prideful Colonel refuse to drop his weapons. As the entire Repliforce is labeled Maverick, General starts a coup for independence, wishing to avoid conflict. Sigma then merely watches as the two groups destroy each other, but to ensure his plans go smoothly, Sigma also sends Double to spy on X. As General goes paranoid and loses his faith in peace, he orders the construction of a satellite laser, the Final Weapon. After General is defeated by X, the weapon suddenly activates, which shocks General, who finally realizes he's been a pawn the whole time. As X goes after the core of the satellite, he finds Sigma, who tells his plan worked perfectly and proceeds to attack X.

On his initial form, Sigma appears in a cloaked, grim-reaper like appearance, which can only be damaged with Rising Fire/Ryuuenjin. On his second form, he uses his large scythe, tossing it around to electrify either the floor or a wall, then sending boomerangs or shooting a laser beam from his eyes. This form is weak to Lightning Web. In the final phase of the fight, Sigma takes on two distinct forms, each with it's own lifebar. One of the forms is a big head which appears on the ground and either shoots wind to push the player into a spiked wall or sucks air then spits lots of scrap metal. This form is weak to the Ground Hunter. On the other form, Sigma appears as a large floating torso carrying a big gun, which he uses to either fire a thick beam that sweeps the entire floor or a bigger beam of light. This form is weak to Soul Body. In between the two forms, various robotic heads will appear to attack the player.

Even though Sigma is destroyed, the Final Weapon is still active, so General appears and sacrifices himself to stop it.

Mega Man X5
Somehow, Sigma was able to interact with the consciousness of Dr. Wily within the virus, which revealed Zero's true nature to Sigma. Intending to "awaken" Zero, Sigma orders the bounty hunter Dynamo to hack into the systems of the space colony Eurasia, setting it into a crash course towards Earth, while he himself prepares a trap for X and Zero. Sigma emerges in a statue construction site, where he makes all mechaniloids go Maverick, so X and Zero rush to the place and confront Sigma. Sigma is fought as the very first boss, appearing as a giant floating head.

As Sigma is destroyed, the ensuing explosion scatters the Sigma Virus all around the world, which was Sigma's plan all along, as he lost on purpose. Soon after, the Hunters learn that Eurasia will crash into Earth, so they run against the clock to retrieve the parts necessary to power the Enigma laser. However, the laser merely delays the crashing colony, giving them some more time, which they use to retrieve parts to power up a space shuttle, while Zero notices how his energy has been growing due to influence of the virus. Zero decides to pilot the shuttle by himself to crash against the colony, successfully destroying the colony and escaping from the shuttle at the last minute. Even so, the wreckage of the colony still leaves the planet badly damaged. After Zero is rescued, the Hunters pick on Sigma's readings, so X and Zero go to investigate. X attempts to convince Zero to return to base, worried about the energy growing within him, but Zero refuses, and the two fight each other. As the two end exhausted, Sigma finally appears and attempts to attack X, but Zero wakes up and retaliates, forcing Sigma to retreat. X recovers and goes along with Zero to face Sigma, who reveals his plan to merge the Sigma virus with the virus in the colony to force Zero's original programming to emerge.

On his first form, Sigma attacks by shooting lightning balls, energy waves and rushing around the room, sometimes creating small viruses to shield himself. He is weak to Tri Thunder. On his second form, Sigma appears in a gigantic body in the background with the jewel in his forehead being his weak spot. He attacks by using two floating hands, attempting to smash the player or shooting plasma. After a while he will start shooting electric balls and create purple boxes, again to smash the player. This form is weak to the Spike Ball.

After Sigma is destroyed, both X and Zero end severely damaged, with Zero's left to only his upper torso. Sigma uses the remaining of his power to shoot a beam, which pierces both X and Zero. Before dying, Zero is able to shoot a final blast, which destroys Sigma for good.

Mega Man X6
In Megaman X6, Sigma only appears near the end of the game, after Gate is defeated. Gate reveals he's been attempting to restore Sigma, but Sigma's code was severely damaged due to the stress of the Eurasia Incident, and as such Gate was unable to finish his body. Even so, Sigma, now reduced to a half-conscious, barely functional body, nonchalantly disposes of Gate and challenges X and Zero, only remembering his hatred against them.

On his first form, Sigma shoots various forms of energy, either from his mouth or his hand. His weakness is the Metal Anchor. On his second form, Sigma appears in a giant skeletal body, and can only be harmed when he opens his mouth to attack. He initially sends various green drones to fill the room, which can be destroyed for items. He then shoots a huge beam from his mouth or charges a pillar of energy that covers half of the room, alternating between each of the halves. After losing half oh his health, he will start shooting large purple spheres which are difficult to dodge. This form's weakness is the Ground Dash.

Mega Man X7
Much time after the Nightmare incident, X retired from his Hunter duties, which prompted an increase in Maverick activity, as well as the insurgence of various illegal Maverick Hunter groups, among them the Red Alert Syndicate, led by the charismatic Red. During this time Sigma reappears, and taking the guise of "The Professor" starts manipulating Red and his organization. He intended to use Axl, a mysterious young Reploid from Red Alert capable of copying Reploid DNA, to copy the DNA of X and Zero. However, Axl senses something is strange with the members of Red Alert, so he escapes the group and seeks the help of the Hunters. Seeking to bring Axl back, Sigma turns the members of Red Alert against Red, who is forced to follow Sigma's orders, challenging the Maverick Hunters to attract their attention. After Red is defeated on his palace, Sigma finally shows himself and confronts the Hunters.

On his first form, Sigma uses his two guns to shoot while walking around the room, as well as going to the background to shoot from a distance. His weakness is the Wind Cutter, which can interrupt most of his attacks. On his second form, Sigma appears in a giant body called Colossus Sigma, which floats over a black void with various platforms circling him, which must be used by the player to reach his head. His attacks consist of various energy shots, which can be deflected back at him with the Gaea Shield/Gokumonken.

Though he is defeated, Sigma reemerges in a junk body and punches Axl through a wall, promising X and Zero he will return. Just then Red appears, so Sigma attempts to possess him, but Red reveals to be actually Axl in disguise, who shoots him and makes him fall over a large pit.

Mega Man X8
Thanks to the advanced technology at the time, the Jakob Project is created to start colonization of the Moon, with the creation of the Jakob Orbital Elevator and the New Generation Reploids, of which Axl was a prototype. Lumine, director of the Jakob Project, reveals that the New Generation Reploids all possessed the DNA of various Reploids, among them that of Sigma, and as such they were immune to all viruses and able to copy even someone as dangerous as Sigma without any ill effects. However, soon a rebellion starts, with Lumine being kidnapped by Vile and various New Generation Reploids becoming Maverick, and soon Sigma himself revealing to be behind everything. When X, Zero and Axl confront Sigma on the Moon, Sigma reveals that he's been manipulating the Jakob Project since it's inception, intending to destroy the "old world" and create a new, perfect world in the Moon for him and the New Generation Reploids, which he refers to as his "children", because since they all possessed his DNA they could go Maverick at will and instead of going insane they would think like him, and as such were his equals.

Unlike in the other games, Sigma has only one form. He will teleport around the room and attack with his massive sword, eventually shooting energy rings and a laser beam from his eye. His weakness is the Shining Ray/Tenshouha/Ray Gun.

After Sigma is destroyed, Lumine reveals himself as the true mastermind behind the whole plot, stomping on Sigma's dead body and saying that Sigma has fulfilled his purpose and that he won't be returning anymore.

Personality
Sigma has an interesting trait that sets him apart from the other villains in the X series. While most other Reploids lose control of their inhibitions and conscious though, and, for lack of a better term, go insane, Sigma does not. He is able to study and learn new things, such as the reasoning for X's constant worry, Zero's shady past, among other things. He is even able to conceptualize grand-scale plans and effectively strategize while in this state. With most infected Mavericks, we never see their true personality, as it is masked by the virus. However, Sigma shows his true personality all throughout. He is a mean, bossy, stubborn, brilliant, cantankerous, and destructive military strategist, and he he uses this to his full advantage.

His obsession with destroying humanity as well as X and Zero stems from the virus, but one thing that has always set Sigma apart is that he doesn't lose control of himself. Mega Man X6 might be the singular exception, because Sigma wasn't all there due to the damage inflicted on him in the previous game.

Sigma has always been very intelligent and imaginative, and remains so. He keeps his enemies' weaknesses in mind and preys on them (such as X's big heart, Zero's wanting to block out all mention of his bloody past, or Axl's discontent at being called a prototype). Sigma's personality itself, post-infection, has been very manipulative and sadistic. He controlled Dr. Doppler into distributing a placebo antivirus which was instead the virus, manipulated the Colonel and the General of the Repliforce (a military-like group meant to compliment the Maverick Hunters) into a full-scale war, and Blackmailed the leader of the mercenary Maverick hunting group Red Alert, Red with his infected and mind controlled friends into cooperating with him in fighting the Hunters.

Appearances in other media
Sigma appeared in the episode "Mega X" of the Mega Man cartoon series, although his name on Dr. Light's laboratory computer erroneously spelled "Cigma" as Mega Man X explains him and his involvement with his 2 fellow Mavericks Vile and Spark Mandrill during X's pursuit of them in the past.

Project X Zone 2
Sigma makes an appearance in his X4 body as a non-playable boss character in the crossover video game; Project X Zone 2.

Marvel vs. Capcom: Infinite
Sigma (in his original form from Mega Man X) is set to appear as a DLC and also during the game's storyline, uses the Infinity Gems to fuse with Ultron to create a new form Ultron Sigma which will serve as the game's final boss.

Crosspedia Entry
The former leader of the 17th Elite Unit of Maverick Hunters. He is X's greatest foe, having faced him countless times.

Boasting incredible combat abilities, decision-making, and leadership, Sigma is considered in some circles to be the most powerful Reploid in existence. His subordinates implicity trust him, and even X also learned his combat skills under Sigma's command.

One day, however, Sigma suddenly rebelled against the humans he was designed to coexist with, causing him to be branded as a Maverick. Although X and his comrades regularly subdue him, Sigma has revived himself no fewer than three times. His cunning plans have generated chaos and mayhem across the world, including the incident where he pitted Dr. Doppler and the Repliforce against X and Zero.

The reason for his rebellion appears to be the presence of the "Sigma Virus" inside his body. However, almost nothing is known about the virus, including its origin.

​Trivia

 * Sigma is similar to Ultron (Marvel). Both are artificial intelligences who want to destroy mankind with the ability to return with new powerful bodies after being defeated and to possess robots and machinery.
 * Sigma has also been confirmed to be the main the main villain of Marvel vs Capcom Infinite with Ultron
 * He also shares similar characteristics with Makuta Teridax from the BIONICLE universe:
 * They both served the side of good before their corruption.
 * they both manipulated various characters throughout the series,
 * both are Complete Monsters.