Sigma

Sigma (シグマ) is the main antagonist of the Mega Man X series. He serves as the final boss in all games except Mega Man X: Command Mission and Mega Man X8 (in the former, he makes no appearances and in the latter, Sigma is the penultimate boss). Created by Dr. Cain, Sigma was considered the finest of the Reploids and was the first leader of the Maverick Hunters, peace-keeping Reploids who defend humans against their renegade counterparts. Although he was once honorable, Sigma unexpectedly goes Maverick in the beginning of Mega Man X and rebels against humankind. 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 insane with each transformation. His primary enemies are X, Zero and, more recently, Axl.



Before Mega Man X
As the former leader of the Maverick Hunters, Sigma was originally the most advanced Reploid of his time. Dr. Cain implanted the latest circuitry designs into Sigma, which were theoretically supposed to prevent him from going Maverick. He was placed in charge of the 17th Elite Unit of the Maverick Hunters, and led them to victory multiple times.

One day, the Maverick Hunters received reports of an overwhelmingly powerful "Red Maverick" that has destroyed an entire squadron of Hunters (the Gamma unit). While investigating, Sigma, along with his unit, tracked it down to an abandoned laboratory. It is here that Sigma encountered Zero, the last product of Dr. Wily. Zero carried with him the malicious "Maverick Virus" which powered up his abilities and turned him into a "blood-thirsty god of destruction." Sigma was beaten badly by the maddened Zero, but managed to smash the energy crystal in Zero's helmet, which transferred the Virus directly into Sigma, infecting him. Zero lost consciousness, and Sigma limped away from the battle, ordering his men to take the body of Zero back for study. The virus begins to mutate and adapt to Sigma's own programming, eventually fusing entirely with his mind to form the Sigma Virus, which when it infects a Reploid implants Sigma's mind into the victim.

Mega Man X
Sigma's advanced circuitry seems to do its job, as he seemingly remains stable for months after the lab incident. He gradually succumbs to the virus inside of him and grows more volatile. Without warning, he leads a mass revolt among the Reploids, declaring total war on humans, which is seen in the Day of Σ. Many Maverick Hunters follow Sigma out of loyalty, leaving Zero in charge of the organization. By this time, he has reformed and become a powerful Maverick Hunter. X, the last creation of Dr. Light and the base model for every Reploid, decides to join Zero as thanks for saving his life. X and Zero battle through the Maverick regime, and it is X who finally destroys Sigma. But though his physical body is scrapped, Sigma's "soul" (the Virus) survives. After the end credits roll, Sigma's face appears on a blue monitor and warns X that he will be back.

In the game, Sigma first sends his pet Velguarder to fight, before he fights using a beam sword. Sigma mostly attacks by dashing and wall jumping. After defeating his first form, Sigma's head attaches itself to a canine-like giant body, called Wolf Sigma. This form can only be damaged by targeting the head, and it attacks X with claws, electricity, and fire.

It's interesting to note that his persona in the game's remake, Mega Man Maverick Hunter X seemed to be significantly different, since he seemed to care more about seeing X's full potential in this game than trying to exterminate humanity (which was the case in the original game). For one thing, Sigma, in the original game, was visibly upset at X for the destruction of Velguarder as well as many of his forces, while as in the remake, he seemed to be almost glad that he destroyed them. When he was defeated by X in the remake, he also seemed to be almost glad to have his original body be destroyed. It's unknown why they made the change.



Mega Man X2
Just as he said he would, Sigma returns and assumes leadership of his Maverick forces. He gains a new robot body with the help of the X-Hunters, a trio of vengeful Mavericks who worship him, and becomes "Neo Sigma". He also oversees the "Unification" plot, capturing and re-assembling of the remains of Zero, whom he reprograms to kill X in the final battle of the game. Sigma attacks in a new form, armed with clawed hands, but X thwarts his plans and destroys him again. This marks the first time Sigma's viral form is seen, as the Final Boss as the game. Zero is then restored to his rightful place in the Maverick Hunters, and given his own command as leader of Special 0 Unit.



Mega Man Xtreme
Mega Man Xtreme weakness:
 * Form 1: Electric Spark, Speed Burner
 * Form 2: X-Buster/Rolling Shield

Sigma uses a hacker named Techno to hack into the Mother Computer of the Maverick Hunter base. Noticeably more confident than previous times, Sigma taunts X after he's beaten the first time and even calls his defeat at the end of Normal Mode merely a retreat. It's only when he's defeated on Hard Mode that he seems to succumb to X.

Sigma has the same forms from the first Mega Man X, complete with the same weaknesses.



Mega Man X3
Sigma resumes his threat when he infects the Reploid scientist Dr. Doppler, who has developed a revolutionary new anti-virus to repel Sigma's influence. Sigma uses him to stage the revolts in Doppler Town, a Utopian city established on the principles of peace. Once Doppler is unmasked as a pawn, Sigma emerges in a heavily-armored form, "Kaiser Sigma". After he is defeated for the third time, Sigma's "Soul" appears in the form of a wire-frame head and threatens to possess X's body to replace its own. After chasing X through the flaming wreckage of the base, Sigma finally corners him. If Zero did not end up critically wounded at any point during the game, which would have forced him to leave the war to X as he was repaired, Zero appears and utilizes the anti-Virus created by Doppler to erase Sigma for the time being. If Zero did end up critically wounded, including the method by which X receives the Z-Saber, Doppler uses the anti-Virus and sacrifices himself to destroy Sigma's programming.



Mega Man Xtreme 2
In Mega Man Xtreme 2, Sigma appears in Extreme Mode after the defeat of the Soul Erasers Berkana and Gareth, where it's revealed he was behind the Erasure incident. In a rare instance, he's pleased that X defeated Berkana, claiming she went too far in her greed.

Sigma's first form is the same from Mega Man X2, "Neo Sigma", but his second form is new. The color of his second form is initially orange, but later alternates between blue and red, which can only be damaged by X while he is blue, and by Zero when red. His weak point is the big lion-like face in his chest.



Mega Man X4
Sigma was thought to be suppressed forever after Zero distributed the anti-virus created by Doppler, but he still manages to return. In the introduction of the game, Sigma, assuming a Grim Reaper-like appearance, acts as a double-agent between the Mavericks and Repliforce, a benevolent squadron of Reploids who assist the Maverick Hunters. Sigma's true motive is to conspire against Repliforce and turn it into a rogue enemy. He stages the bombing of the airborne metropolis Sky Lagoon, which plummets to the ground in the opening of the game.

With in-fighting between the Hunters and Repliforce threatening to destroy them both, Sigma increases his influence over the paranoid General of Repliforce. The General, an outspoken advocate of Reploid independence, loses all faith in peace and prepares a satellite laser attack on all humans ; fortunately, X storms the space weapon and stops the General before he can turn its sights on Earth. In the end, Sigma is revealed as the true mastermind and battles X himself, armed with a new body and a scythe. Despite his defeat at X's hands, he succeeds in part by destroying Repliforce.

If the game is played with Zero, Sigma reveals a portion of Zero's past involving their first encounter that possibly made Sigma a Maverick.

Interestingly, this is the only game where all of Sigma's audio pre-battle quotes are threats (eg, "Tremble with terror! YOU ARE FINISHED!" or "Are you ready for your final journey?!")



Mega Man X5
It is some time before Sigma surfaces again. During his absence, Sigma traced Zero's origins to Dr. Wily, and hatches a plot to unlock Zero's "true" power -the Zero Virus- inside him. Sigma also adapts his programming to completely overwhelm the anti-Virus; the Sigma Virus quickly begins spreading everywhere, turning peaceful machines and Maverick Hunters alike into violent servants of Sigma. The Maverick leader also enlists the help of a Reploid bounty hunter named Dynamo to crash the orbiting space colony Eurasia into the Earth, as well as to hinder the Hunters' plans of stopping the collision.

Sigma's ultimate goal is to mix his own viral code, which is spread across Earth, with the original Zero Virus, and become all-powerful. Sigma hesitates to kill Zero, intending to make him "remember" who he is and revert back to evil. He fails to make Zero remember, and both X and Zero defeat Sigma's new "Final Sigma W" body, (which has been powered by Dr. Wily, although it may be just speculation) and "Gamma Sigma's" (?) giant robot form (which stands several stories high). In the aftermath of the battle, Zero's severed torso lies dormant on the floor. X picks Zero up and tries to get him to respond. The remains of Sigma's head lying nearby suddenly becomes active and fires an energy laser directly at X and Zero, catching both of them in the chest. As Zero's body falls from X's grasp after Sigma's laser, he manages to fire one last blast from his Z-Buster and finishes Sigma. X is critically wounded in the battle, both from the battle itself and Sigma's final attack (The force of the laser being so strong that it ripped through his body and destroyed his entire lower half and arms) but he is eventually rebuilt and returned to the Hunters.



Mega Man X6
Three weeks pass as the human population moved underground to survive the devastation and pollution left by Sigma's last attack. Sigma himself is quickly resurrected by a renegade Reploid scientist, Gate, who is angry at the scientific community for rejecting his advanced Reploid designs. He becomes a Maverick after coming into contact with a piece of rubble that contains signatures of the Zero Virus. Gate then uncovers Sigma's remains, and proceeds to rebuild him. However, due to the stress of spreading the Sigma Virus during Mega Man X5's "Colony Incident", Sigma's programming is damaged beyond what Gate can repair, and he is reduced to a half-conscious and barely-functioning wreck of his former self. Gate's work on Sigma's new body is unfinished by the time X confronts him at the end of the game. He seems to remember little more than his rage toward X and Zero, and speaks in a garbled voice. Although it seems as though Gate rebuilt Sigma merely as a backup plan to further his own goals, Sigma is quick to finish Gate off after X and Zero finally defeat him in battle, stating "Oh please, I did not die, nor did I need your help. Now be gone!" This is the only instance in Mega Man X6 that Sigma speaks coherently. While you only fight his first form in Mega Man X6, a similar form appears in the ending cinematic for Mega Man X7.



Mega Man X7
Mega Man X7 weakness:
 * Form 1: X-Buster (X)/Hieijin (Zero)/A-Bullet (Axl)
 * Form 2: X-Buster (X)/Z-Saber (Zero)/G-Launcher (Axl)

Sigma reappears yet again, under the alias of "The Professor", to manipulate the hunting organization known as Red Alert. His plan is to use a mysterious young Reploid named Axl to copy D.N.A. signatures of X and Zero, then implant them into destructive war machines. The plan fails when Axl flees Red Alert and sought asylum with the Maverick Hunters. After being defeated, Sigma (who appears in a similar form to his first form in Mega Man X6) punches Axl through a wall before vowing to X and Zero to return in a new body. Red, who had been defeated and presumably killed, reappears, and Sigma tries to take over him. Red is revealed to be Axl having taken on Red's form, and then blasts Sigma out of a window.



Mega Man X8


Mega Man X8 weakness:
 * Copy Sigma (in Gateway): Shadow Runner (X)/Rasetsusen (Zero)/Black Arrow (Axl)
 * Real Sigma (in Sigma Palace): Shining Ray (X)/Tenshouha (Zero)/Ray Gun (Axl)

Sigma's next plot was very complex, and it wasn't even him behind the entire scheme. It turned out that Axl was a prototype for a new generation of Reploids. These next generation Reploids possessed advanced copy abilities, and Alia discovered that the copy chips bore copies of Sigma's program among other powerful Reploids. Sigma instigated a new Maverick revolt with these new Reploids as the humans were evacuating Earth in hopes of finding a new home on the Moon. The revolt was stopped, Sigma was completely devastated, and the real mastermind, Lumine, the manager of the project, was revealed and beaten. Before his death, Lumine made a startling claim: According to Lumine, Sigma was dead and not returning. It is believed that the reason Sigma would not regenerate within another body after his final defeat is that he was on the Moon where the virus might have weakened in the vastness of space and got completely deleted. (Although he was also defeated in space in Mega Man X4; However, this was on a large battle weapon, not on the Moon). There also might be a lack of available bodies, and his last body was hardly finished. However, his DNA is included in every copy chip in all the next generation Reploids, so technically all new generation Reploids are infected with the Sigma Virus, and possibly Lumine, too. It is unknown if Lumine's claims are true, although his absence in Mega Man X: Command Mission, as well as the entire Mega Man Zero and ZX series so far would suggest that he is not coming back, thus being Sigma's last appearance.



Abilities
As the former leader of the Maverick Hunters, Sigma is a capable military leader, rendering him a devious and strategic opponent. When he turns Maverick, Sigma remains a charismatic leader, and is revived on many occasions by Reploid and Maverick admirers alike. Due to the Wily Virus in his circuits, he can survive seemingly anything and always return for more. He is fond of incorporating himself into battle suits which are vastly larger than his "regular" form. Sigma is also a skilled manipulator, managing to turn various Reploids, Maverick Hunters, and Mavericks to his side. In fact, there were few instances in the entire series where Sigma wasn't pulling the strings.

Other media

 * Though not a starring character, Sigma was referred to in an episode of the 1994 Mega Man cartoon, where X, Vile and Spark Mandrill go back in time. His profile, shown by X, mistakenly spells his name as Cigma. The only lines Sigma has is when Vile contacts him near the end of the episode.


 * Sigma also appears in a short unlockable OVA in the game Mega Man Maverick Hunter X for the PSP entitled "The Day of Sigma". It shows the Maverick Hunters prior to the events of the game under Sigma's command, before he ultimately revolts. It should be noted that the events in this OVA coincide more with the canon of Mega Man Maverick Hunter X than with the original game.


 * In the Rockman X manga, Sigma starts the rebellion by killing a Maverick Hunter (Kyle) that was against him, and convincing various Hunters to join him by saying that Reploids are superior to humans, and they should no longer take orders from them. When Spark Mandrill was giving up the fight against X, with fear and saying he would tell all of Sigma's plans to him, Sigma uses a giant hologram of him (a flying mechanism) to kill Spark Mandrill. Before the fight against Armored Armadillo, it's shown that Sigma made a scar on Armadillo's left eye because he doesn't follow his orders to defeat X in the forest. After defeating the eight Mavericks, Sigma appears and challenges X.

Trivia

 * Sigma (&Sigma;) is the 18th letter of the Greek alphabet, and is used in mathematics to denote series', finite or infinite sums of variables. The &Sigma; symbol is often seen on Mavericks from Sigma's army.


 * There are three versions of the way Sigma got the scars on his eyes:
 * 1) Zero damaged Sigma's face when they fought (However, since that same fight had Sigma losing his sword arm, half his face, and part of his legs, and yet were repaired by the time Mega Man X begins, it's most likely those deformations were fixed.),
 * 2) X damaged his face in The Day of Σ (although he could have repaired the one done by Zero); Ironically, after Sigma's head merges with the canine robot in the game, his face resembles his face deformity received against Maverick Zero,
 * 3) Sigma did it himself after going Maverick in the manga, by using the heat of the "weapon" (his fingers) he used to shot Kyle to make the scars.


 * Sigma is called Cigma in the Mega Man cartoon series.


 * According to Keiji Inafune, Mega Man's creator, Sigma's appearance was largely inspired by Doc Robot from Mega Man 3, one of the few antagonists in the series not designed by Inafune himself. He then stated that although Mega Man 3 is not a favorite of his from the original series titles, Sigma is the only creation of his or any of his staff to borrow from that game's wealth of characters.
 * There were some hints in Mega Man ZX that Sigma might have lived on via Model W (Model V in the Japanese version), for instance, sometimes Serpent speaks with Sigma's voice in the dialogue, not to mention that he says the same exact thing that Sigma said on Day of Sigma to Aile and Vent (I.E., "Evolution Requires Sacrifice"), in fact, Sigma and Serpent's origins were extremely similar.
 * Sigma was technically a fake villain in his last appearance in X8, as he was played out to be the main villain, when the true main villain, Lumine, appears after he is defeated.