Characters / Mega Man X: Sigma

Mega Man X | Main Character Index
Heroes (X | Zero) | Villains (Sigma | True mastermind) | Maverick Bosses | Supporting Cast

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Sigma

Voiced by: Mugihito (JP), Charlie Fontana (EN, X4), Walter Roberts (EN, X7), Dave Petit (EN, X8), Gerald Matthews (EN, Maverick Hunter X), Chandler Van Fossen (EN, X4 redub), Jim Byrnes (EN, animated series), Chris Tergliafera (EN, Marvel vs. Capcom: Infinite)

From Mega Man X DiVE.

The primary antagonist of the X series. One of the most advanced and powerful Reploids ever made, he was the greatest creation of Dr. Cain. When the Maverick Hunters were formed, he was chosen to be their leader and uphold peace around the world, leading them to many victories and successes. One fateful day, however, following an encounter with the recently-unearthed Zero, he was exposed to the Maverick Virus, a virus that changed the thought processes of a Reploid and usually made them unruly and violent.

Instead of simply being infected, however, Sigma’s advanced nature caused him to became one with the virus, and the process turned him into a murderously insane maniac bent on ending the human race. He’s appeared in many bodies throughout the series, and Sigma is never usually the same each time. No matter what form he takes, however, one thing is always consistent: as long as the Sigma Virus lives on, Sigma lives on.

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A-H

• Ambiguous Start of Darkness: From the first game's manual, it was always established that he led his Maverick rebellion as he believed that humans were limiting the evolution of Reploids. However, later games would establish that Sigma went Maverick after his fateful encounter with Zero, which would get the former infected with the Maverick Virus to merge with Sigma's mind to form the Sigma Virus. It is therefore unclear whether Sigma turned evil entirely because of the virus messing with his mind or Sigma was always resentful of humans with the virus merely giving him the means to carry out his rebellion. However, some of his characterizations pre-virus (in the X4 flashback and an archive of his old data on Dive) showcase him to be fairly reasonable.
• A Nazi by Any Other Name: For the first few games, his attitude about humans can be summarized as "the inferior need to be exterminated so the superior can thrive". He then extends this attitude towards earlier reploid models for the sake of the Next Generation ones.
• Animal Motifs: Wolves. He has a pet robot wolf named Velguarder, his One-Winged Angel form in the first game is a large robotic wolf, and his symbol is the Greek letter Sigma designed as a wolf.
• Anthropomorphic Personification: He's the living will of the Sigma Virus - it's even named after him. It's heavily implied that as long as the Sigma Virus exists there's always a chance that he could return.
• Arch-Enemy: To both protagonists X and Zero.
  • Sigma is greatly interested in X's potential and wants to use his body to usher in a new age of Reploid supremacy. Sigma even comments on how he and X are "always destined to meet".
  • Zero is the one who infected Sigma with the virus in the first place, and is greatly disturbed by what he did to the former Maverick Hunter. On Sigma's end, he indirectly causes Iris' death, even mocking Zero about it, and later goes along with Dr. Wily's posthumous plan to turn Zero into the monster he was meant to be.
• Arc Welding: His evolution talk calls to mind later Big Bads Serpent and Lumine. It's not clear where Inafune was going with this, as the remake series was canceled.
• Arc Words: "Evolution requires sacrifice."
• Artificial Zombie: In X6, he is brought back into a half-dead state by Gate.
• As Long as There Is Evil: Tells X this when defeated in Xtreme, promising to haunt him and Zero for as long as they live.
• Attack Its Weak Point: Most of the time, his second body's weak point is located on the head.
• Asskicking Leads to Leadership: Dr. Cain built Sigma to be the leader of the Maverick Hunters and consequently to have the power to match the post. At the time of his creation, Sigma was the most advanced Reploid in the world both on a physical level and with the most advanced anti-virus software installed that would, in theory, prevent him from going Maverick and thus turning that power against humanity. He continues to hold true with this more or less as the leader of the Mavericks.
• Ax-Crazy: His sanity seems to wane as the games go on, where he becomes less concerned with helping Reploids advance in their development and far more obsessed with killing the heroes while wiping out millions of innocent lives in the process. And in the reboot of the first game, he already shows signs of this, such as laughing maniacally while looking down at the ruins of a city he obliterated via missile launches.
• Back from the Dead: Again and again and again and again... at last count, he's been killed ten times. In the strictest sense, the only times where it seemed like his death might stick were in X3, where he's first hit by a real anti-virus, X5, where Zero destroys him after most of the Sigma Virus has been eradicated from the Earth, and X8, where he is destroyed on the moon, and hasn't been seen since.
• Badass Boast: He loves giving these out. Not just prefight ones, but even after he has seemingly been defeated, most notably as The Stinger for the first game.
• Badass Cape: A staple of Sigma's. Most notable in his X1 and X5 forms, but in X4 he wore a Grim Reaper cloak and in X2 he only wore a cape in artwork. Subverted with his tattered robes in X6 and X7, which serves to make him look beaten and haggard rather than intimidating.
• Bad Boss: In the non-canon Vile Mode of Maverick Hunter X, he allows Vile to kill a ton of his Mavericks, including his high-ranking generals, to test Vile's potential.
• The Bad Guy Wins: Sigma's actions in X8 ensure that new generation Reploids will continue to go Maverick for eternity despite their viral immunity, effectively ensuring that his legacy will live on no matter what. Only in the Zero series does his plot finally crumble. He also defeats both X and Zero in The Day of Sigma, successfully launching a missile strike.
• Bald of Evil: He is built to be bald, unlike many other robots, and is a terrible Reploid, although he was once the heroic leader of the Maverick Hunters.
• Batman Gambit: In X4 and X5, his plans rely on the personalities of General, Colonel, X, Zero, and Maverick Hunter policy. This is turned way up in the manga rendition of X4, where he relies on the Repliforce Coup (and was the setup of it thanks to Double), wherein all the Repliforcers are absolutely crazy (like the necromantic Web Spider or the "I'm going to kill my own troops and drive a super train through a populated city" Slash Beast).
• Batter Up!: His "Gangsta" variant in X DiVE has a baseball bat as his default weapon.
• BFG: In X7, one of his attacks has him pull out one of these.
• BFS: Special mention to X8's BFS, the aptly-named "Σ Blade" which in addition to length is probably the widest and thickest sword he's ever used as well. The animated opening to X3 depicts the first game's saber as a BFS.
• Big Bad: Of the entire series as a whole and of nearly every individual game, with the exceptions of X6 (where Gate is the main villain and uses Sigma as a Godzilla Threshold), and X8 (where Lumine takes advantage of Sigma for his own plans).
• Big "NO!": Lets one out after his defeat in X8.
• Breath Weapon: In Maverick Hunter X, Sigma's wolf form can breath fire from its mouth. In X5 and X6, Sigma can fire lasers from his mouth.
• Brought to You by the Letter "S": All the Mavericks directly under Sigma would have his symbol somewhere on their person.
• Came Back Strong: In X5. After getting inflicted with Doppler's antivirus in X3, and getting destroyed again in X4, Sigma is back yet again, and has not only completely overcome the effects of the antivirus, but is even more powerful than ever. He can bind himself directly to machinery and transform it to his will, and trying to destroy him again only allows the Sigma Virus to spread across the entire planet!
• Came Back Wrong:
  • Gate revived Sigma. Unfortunately, he apparently ruined his sanity in the process. He gets better by X7, though. Curiously, when seen holding conversations with Red as "The Professor" and during the ending of X7, Sigma appears in a state of disrepair not unlike in the sixth game. This suggests that, between spreading himself too thin across the globe during the Earth Crisis and his botched resurrection only a few weeks later, while Sigma's mind eventually recovered, the damage to his body and programming/viral coding may have been permanent, perhaps leading to his ultimate defeat in the following installment.
  • It's implied that this first happened earlier, just after X3. At first, Sigma could manifest in his viral form and attempted to possess X to finally defeat him, only to be struck with Doppler's anti-virus. While his return can be explained by Berkana's experiments, he never again tries to possess X or assumes his viral form again, and instead shifts his focus to Zero.
• Canine Companion: Velguarder. He sics him on you before fighting you himself in the first game.
• Classical Movie Vampire: He has a Halloween variant in DiVE whose attire pretty much mirrors the classic Dracula.
• Cloak of Defense: In the manga adaptation ofX1, Sigma's cape is able to protect him from enemy attacks. This becomes essential to X surviving the destruction of Sigma's fortress when he uses the discarded cape to protect himself during the descent.
• Clone Angst: In the X1 novelization, Sigma has a freakout when he discovers that he and all other reploids were made from X's designs making them "flawed copies." This of course leads to his rebellion.
• The Coats Are Off: He throws away a cloak before fighting you in X1, X4 (after X/Zero burned it off), and X5.
• Continuity Nod: His One-Winged Angel from X5 is Gamma, the Final Boss from Mega Man 3. And it was given to him by Dr. Wily.
• Create Your Own Villain: In a meta-sense. Sigma claimed humanity and the Maverick Hunters would turn on Reploidkind if they stepped out of line, thus necessitating their destruction. His and his successors' many years of attempted genocides and near-apocalypses would go on to create Dr. Weil.
• Death of Personality: Neither X nor Zero ever were made aware, but X4 and Word of God clued in the audience that the "Sigma" who incites war throughout the series isn't even the genuine article. Commander Sigma, the Maverick Hunter, ceased to be when he first encountered Zero, long before the series even started. His consciousness was overtaken and assimilated by the Maverick Virus, causing it to mutate into the Sigma Virus, which walked around in his body until X first destroyed him.
• Deader than Dead: In X8, as he died on the moon. This is somewhat confirmed with his absence in Command Mission (set in 22XX). Coupled with the events of X4-X7, it is speculated that the Virus may have lost much of its potency on the moon, judging by Sigma's unfinished true body and Lumine's remarks after Sigma is defeated. Even then, the presence of his DNA in the copy chips of the New-Gen Reploids (whose production was restarted later on) likely provides a backdoor for him to return anyway. However, By the time of Mega Man Zero, X is said to have used the Mother Elf (a "Sigma Antibody Program" created from the Maverick Virus data in Zero's body) to erase all traces of Sigma's DNA and end the Maverick Wars.
• Degraded Boss: In the later part of the secret final stage of X8, you can see multiple New Gen Reploids transforming into Sigma to fight you. They all die easily like other mooks (though they're among the harder of mooks), and their attacks aren't as strong as real Sigma's.
• Disc-One Final Boss: In X8, which served as a Meta Twist since usually Sigma was the one who was manipulating the supposed main bad guy, instead of the main bad guy manipulating Sigma.
• Double Weapon: In X7 his main weapon is a giant rifle that he can split into two smaller rifles.
• Enemy Civil War: His X4 plan is to set one of these up. It works perfectly because the Repliforce is not very bright.
• Energy Ring Attack: In his final form, Sigma can fire rows of blue energy rings from his hands.
• Engrish: Used deliberately in X6 to show how badly deteriorated his mind is after his imperfect resurrection.
• Even Evil Has Standards: In Xtreme 2, a throwaway line in his reveal implies that Berkana's entire "Soul Erasure" plan to feed upon the DNA Souls of Reploids was too far, even for him, and congratulates the Hunters for dealing with her — though he also promptly comments that the whole affair amused him enough to not intervene until she was dead, so he's still a bastard.
• Evil Costume Switch: While a commander in The Day of Sigma he has a relatively simple green look. After getting his eyes scarred and going Maverick, he adds spikes on his wrists, extends blades from his back, and equips a flowing red cape.
• Evil Is Bigger: Regardless of what body he's using, he's always much larger than X and Zero.
• Evil Is Not a Toy: Gate admits that he's risking his own life bringing Sigma out, but he has no choice at this point with X/Zero having exhausted all other options. Sigma quickly shows Gate he should have taken his chances and blasts the scientist away.
• Evil Plan: It's always to destroy the humans, somehow.
• Evil Sounds Deep: Particularly in X4, where his voice sounds similar to a slasher movie villain, in X7, where he sounds like Dr. Claw, and in MVCI where he has a voice remarkably similar to Mohammed Avdol.
• Evilutionary Biologist:
  • He follows the robotic version of this, especially in Maverick Hunter X, where he wants to see the true potential in Reploidkind. His plan is to prove this potential by pushing X to his limits.
    Sigma: "Evolution requires sacrifice."
  • In the aftermath of the X vs. Zero battle in X5 (should Zero not go Maverick), Sigma similarly expresses disappointment that Zero was unable to evolve to his "true self." Should Zero be brought to the final battle in Zero Space against Sigma, Sigma gives one more try at tempting Zero with the power he'd (re)gain when awakened, but Zero doesn't bite.
• Expy: Has most of his traits from Char's Counterattack as a Dark Messiah judging humanity by rebelling against them as another race in a much brutal fashion and even his legacy goes on afterwards transcending to another plane of existence and transferring his another kind into another body. He is shown to be manipulative to his allies and treats them nothing more but a piece of pawn in his game and develops a rivalry with the blue schemed protagonist throughout the series.
• Eyes Are Unbreakable: The attack that gave him his trademark scars did nothing whatsoever to his actual eyes. Subverted when Maverick Zero does, in fact, gouge out one of his eyes along with half of his face, and in Maverick Hunter X where he, in his One-Winged Angel form, is shown having his right eye missing.
• Eye Beams: In X4 and X8.
• Eye Scream: Both Maverick Zero and X have gone for his eyes in the past. The latter inflicted burn scars in the process. Since Sigma's a robot, we are usually spared the worst of this trope.
• Face–Heel Turn: Was once a member of the Maverick Hunters and a noble Reploid at that, but then he was infected by Zero's virus and the rest is history.
• Faking the Dead: In X5, he straight up is taken out in the very first boss fight solely to let his virus spread across the Earth, forcing the heroes to put any proper searches for him on the backburner to deal with the Space Colony Eurasia. He doesn't actually show up again after that until the endgame in the aftermath of the X versus Zero duel to try to pick them off. However, the duo aren't really surprised at all, given it was obvious that something of Sigma was buried deep in the ruins with how much concentrated virus was in there, and unlike most of the rest of the series it's explicit that this game was his plot from the start, his teamwork with Dr. Wily aside.
• Fallen Hero: He wasn't just a random Maverick Hunter who turned to evil: he was their leader and became the biggest threat to the world and the leader of the very enemies he fought in the past.
• Fantastic Racism: Once he was infected, his compassion for those who served under him in the Maverick Hunters becomes twisted by the Maverick Virus. Now he believes humans to be inferior to Reploids, and most of his plans through the series involve the slaughtering of the human race.
• Fantastic Terrorists: Terrorizes and razes multiple locations to help his cause of overthrowing humanity and achieving his idea of Reploid evolution.
• Fatal Flaw: Pride. His being infected in the first place is partially his fault for screwing around when fighting Maverick Zero in X4. That and he has some terrible judgment regarding his battle bodies, even if they aren't complete.
• A Father to His Men:
  • Back when he was still commander of the Maverick Hunters, when they managed to corner the single rogue maverick (Zero), he insisted going in by himself as he couldn't bear the idea of losing more of his men.
  • The second and third Mega Man X DiVE Halloween events (ironically enough) and the Reploid Air Force chapter give a glimpse of what Sigma was like before he was corrupted - a genuinely pleasant and nice guy who was supportive of his comrades and subordinates, and even a bit playful at times, in a good way. Both RiCO and ViA can't help but feel a bit of whiplash from meeting the series Big Bad from before he became evil. It makes his fall from grace look far, far more tragic in hindsight, especially considering he had no agency in said fall whatsoever from the moment he was infected.
• Faux Affably Evil: Only in X1, before his decreasing sanity, he acts quite polite to X before their fight, congratulating him for making it this far, yet saying he is almost as good as he was.
• Fighting a Shadow: Eradicate his current body, his viral self is still intact. Erase it, and a backup copy will pop up later in a new body. It takes killing him on the moon to finally destroy him, supposedly because his viral form will (presumably) just fade away to nothing with no other robots to infect there.
• Fire, Ice, Lightning: Sigma's final form in X4 has a move consisting of three robotic heads- one blue, one red and one yellow. The red one attacks with fire, the blue one with ice and the yellow one with lightning.
• Final Boss: Appears as the final adversary in all games in one form or another with the exception of X8 and Command Mission, the former where he's the penultimate boss and the latter where he's nowhere to be found.
• Fling a Light into the Future: A villainous take on this. In X8, Sigma seemed to finally acknowledge his increasing decay and limited time, so he hijacked the production of New Generation Reploids to instill his personal data across all of them — save for Axl, who narrowly avoided the impromptu "adoption". While Sigma's next stand appeared to have finally been his last, it didn't matter, because he effectively created an entire line of Sigmas to succeed him. Unfortunately for him, all of this effort is eventually undone by the Mother Elf.
• Foreshadowing: Sigma, when trying to recruit General to revolt against humanity, claims that humanity will try to destroy anything that doesn't obey them completely. Come the Mega Man Zero series, as well as Weil's Badass Boast in Zero 3, it turns out Sigma was right. Though it may have been due to constant, genocidal Reploid revolutions that he personally helped cause which made Weil decide Reploids couldn't be trusted with free will.
• Genius Bruiser: A brilliant tactician and genius, and is more than capable of fighting the heroes with giant, muscular bodies.
• Giant Hands of Doom: In his second form in X1, X5, and X7.
• Gone Horribly Right: Sigma was designed with the most advanced anti-virus software at the time of his creation in the hopes he would be able to fight off any infection. When he was infected by the Maverick Virus due to his battle with Zero, his programming did indeed attempt to fight it off by merging with it, destroying his old personality and in the process going from being being infected by the virus to becoming the virus itself.
• Grand Theft Me: Tried to pull this on Red in X7, but failed due to him being Axl. Before that, he also attempted this on X in X3, but either Zero or Doppler blasted him before he manages to.
• Grim Reaper: His first form in X4, while orchestrating a massive civil war between two armies, and then trying to use a Kill Sat to commit genocide. He even comes complete with an Laser Scythe!
• Guns Akimbo: His primary weapons in X7.
• Hijacked by Ganon:
  • He succeeds Wily in this department. The list of his hijackees include the X-Hunters in X2, Dr. Doppler in X3, the Repliforce in X4 (although this was lampshaded by one of the bosses, and Sigma's involvement is strongly hinted at as early as the cutscene right after the intro stage), Gate in X6, and Red Alert in X7. He even pulls this off in both Xtreme games, controlling Techno and somehow behind Berkana and Gareth between the respective stories. Surprisingly, this doesn't happen in X5 and X8; X5 has Sigma acting out a plan made with a partner who's implied to be Dr. Wily, and in X8 Sigma is Hijacked by Lumine.
  • X6 is also an interesting case in that Gate is still the true mastermind of the game, as Sigma's current incarnation is an unstable zombie who was revived simply because Gate thought he needed a backup plan against X and Zero (plus some possible influence from the Maverick/Zero Virus). He just kills Gate after his defeat, and X and Zero go after him because... well, it's Sigma. X practically lampshades Sigma's presence in X6.
    X: Sigma... we don't have time to deal with you. We need to rebuild our world and I can't let you get in our way. It doesn't matter how many times you'll come back... I'll beat you!
• Horned Humanoid: Continuing the Biblical symbolism present in X8, Sigma's true appearance in that game (as opposed to the Copy Sigma fought at the Gateway) is a devil-like figure with slightly distorted facial features, the scraps of metal that constitute his incomplete body seemingly held together only by the Sigma Virus.
• Hover Bot: Shows up as a huge floating head at the start of X5 as a Warmup Boss.
• Humongous Mecha: His X5 and X7 forms are by far the largest bosses in the series.
• Hypocrite: For all his feigned concern about human oppressors disposing of any reploid that fails to obey them, he was perfectly willing to dispose of every reploid on Earth in order to achieve his goal of exterminating humanity with Final Weapon, as well as his use of threats, reprogramming and viruses to compel reploids to follow him/his way of thinking.

I-Z

• I Let You Win: In X5, the first boss fight is against Sigma in the form of a large floating head. After the player defeats him, a virus breaks through Earth, which was what he wanted. Zero clearly states "he lost to us on purpose!"
• I'll Kill You!: In X6, he's reduced to just wanting to kill the heroes, having his mind deteriorate. "THE BADDLE HAZ JUSD BEGUNN!" "IWILLSHOWYOUWHATATERRORISALLABOUT!!" "JUSDIE X!!" "ZELLLLLLO!!!"
• I Need You Stronger: Why he doesn't up and finish X off at the end of The Day of Sigma. He also spares Zero because he doesn't know who he is or exactly what he is.
• Ironic Echo: In the OVA, Sigma tells X that there are times that X should never hesitate to pull the trigger as words of encouragement and also a lecture after an incident where Sigma had to get involved in decommissioning the Maverick due to X hesitating after it used a captured soldier as a Reploid-shield. Sigma later says that exact thing when he is strangling Zero after becoming Maverick to taunt X, and unveiling that he's going to nuke Abel City to the ground as the start of his Reploid rebellion.
• Japanese Delinquents: His "Gangsta" variant in X DiVE dresses up like the typical Japanese school gang leader, complete with a Commissar Cap and a baseball bat for a weapon.
• Joker Immunity: Keeps getting killed (sometimes dying twice in a single game!), but he just will not die due to his form as a sentient computer virus, and since he's in the future with robots galore, there's no shortage of things to bodysurf into. However, he finally gets it revoked in X8, where after getting blown up on the Moon of all places, he finds that there's nothing left to jump into on its barren surface, and dissipates harmlessly and somewhat anticlimactically. Even assuming that didn't finish the job, the Zero series reveals the Mother Elf anti-virus program basically eradicated both the Maverick and Sigma Viruses from the world, ensuring that Sigma would never be able to return.
• Kick the Dog: Employs a particularly bad verbal one to Zero before their battle in X4. After revealing how he orchestrated the conflict with Repliforce, which led to the death of Iris at Zero's hands, Sigma cruelly taunts the emotionally torn-up Hunter with "Iris is waiting for you!"
• Kill All Humans: His goal, in order to lead the way for Reploid evolution.
• Killed Off for Real: Zig-zagged a lot, thanks to his Joker Immunity. In X3 his viral essence was seemingly erased by Doppler's vaccine... only for him to make an Unexplained Recovery in X4. Then he seems to die for real again in X5... only for Gate to revive him out of desperation. He finally dies for real in X8. Even after that, the Mega Man Zero series reveals that his Sigma Virus lingered on and caused trouble years until the Mother Elf finally finished it off.
• Lantern Jaw of Justice: Inverted with his massive Chin of Villainy. Played straight in his pre-infection days, where he genuinely was a noble warrior.
• Large and in Charge: Even before he goes One-Winged Angel, he's pretty tall and the leader of the Mavericks.
• Large Ham: Especially at the end of The Day of Sigma OVA. He's no slouch in the other games, either. And his hamminess grows as his sanity decays to the point that by the eighth game, he's constantly shouting all his lines.
  Sigma: "Come and get me X! The time has come to prove your mettle against me. This fight will decide the fate of all Reploids! The battle may be over, but the war is just beginning! MUWAHAHAHAHAHAHAHAHAHAHA!!"
• Laser Blade: His weapon of choice in X1 and X8.
• Last Breath Bullet: In X5, Sigma starts it by shooting X and Zero at the same time with a back attack. Zero has enough power left to give a parting counterattack as he fades away, finishing Sigma off.
• Letting the Air out of the Band: A computer variant as described on the page after being once destroyed by Zero.
• Lightning Bruiser: In most of his (first) forms, Sigma is incredibly swift and agile, and has incredible strength to go with it.
• Magnum Opus: Dr. Cain created Sigma as the pinnacle of Reploid technology (at the time). He was so advanced that it took the Maverick Virus months to corrupt him, and even then his programming managed to appropriate the virus into his own breed of virus.
• The Man Behind the Monsters: All of the humanoid Sigma's henchmen are all animaloid, save for his various Dragons.
• Manipulative Bastard: Before Sigma was even made aware of his newfound viral nature and began infecting reploids left and right to built his forces, Sigma recruited all of his turncoat elites from the Maverick Hunters by playing into their wants and vulnerabilites, with Maverick Hunter X expounding on them.^note Chill Penguin's inferiority complex, Flame Mammoth's pride, Spark Mandrill's gullibility, Sting Chameleon's ego, Launch Octopus's vanity, Armored Armadillo's loyalty, Boomerang Kuwanger's curiosity, and Storm Eagle's reluctance leads it might have been some measure of leverage on him. He'd repeat this in X4 with a short conversation planting seeds of paranoia in the General, in X5 by gaining Dynamo's loyalties despite his being a mercenary, and in X7 when he planted himself into the chain of command of Red Alert. This all is aside from the regular loyalty of Vile, who Sigma's managed to continue to get to side with him out of his own interests despite having died for him several times. Even without being The Corruption, just talking at any length with him seems to be dangerous.
• Meaningful Name:
  • The uppercase sigma (Σ) is used in mathematics to represent sums. Sigma was built as the "sum" of all Reploids, the ultimate warrior fit to lead the Maverick Hunters. Becomes ironic once he gets obsessed with evolution.
  • Along with Zero's name: Keiji Inafune says that Sigma and Zero basically represent the idea that nothing is absolute. Sigma was a powerful leader of the Maverick Hunters but after Zero passed the virus to him, his allegiance changed. Circumstances can change anything, and nothing is absolute.
• Mighty Glacier: In many of his One-Winged Angel forms, he trades speed and agility for pure power. This is also evident in his first form in X6 where his movements and attacks are extremely slow, but very powerful.
• Mirror Match: Per his playability in DiVE, he can fight against five different versions of himself during Raid Bosses: Wolf Sigma from X1, Phantom Sigma from X4, Final Form Sigma from X4 (the Gunner Sigma and Earth Sigma phase of the final boss), Final Sigma W from X5, and the Sigma Virus from X2.
• Motive Decay: Sigma was once a stated charismatic revolutionary. Upon turning Maverick, his initial goal was for the Reploids to reign over mankind (akin to Magneto) before he became obsessed with the defeat of the heroes. From X2 onwards, Sigma's goals usually switched between trying to obtain new bodies for himself (manipulating others to build them such as Dr. Doppler in X3 or trying to take X and Zero's for their technology, such as the former in X3, the latter in X5 via manipulation of the virus, or using Axl to copy their DNA to build an army in X7), destroy the planet (whether via Kill Sat in X4, Colony Drop in X5, or Space Elevator in X8), or just flat-out destroy X and Zero (a constant in every single X game since X1). Though, really, being corrupted by the Maverick Virus and outright merging with it probably did not do wonders for his psyche.
• More than Mind Control: What makes the Maverick Virus so insidious among fictional infections; it's not an active control that can be broken by killing Sigma.
  • The Maverick Virus starts by rewriting the infected's cognition, making them genuinely believe and feel that the radical and violent views they come to adopt under Sigma's thrall are in fact their own. This is part of what makes curing them so close to impossible, as it fundamentally changes who they are - the only eventual cure being the Mother Elf, an entity specifically designed to manipulate reality using cyberspace to finally eradicate the Sigma/Maverick Virus permanently and fix all the affected Reploids.
  • In X4, Sigma doesn't need to infect a single member of Repliforce. He just plants the seeds of paranoia, triggers a single incident, and lets the Maverick Hunters and Repliforce go to war of their own accord, all achieved by speaking with General for a matter of minutes.
• My Death Is Only The Beginning: As is well-known, destroying Sigma the Reploid only succeeded in unleashing Sigma the virus. This would occur again in X8, where even as he seemed to be dealt his last death, he let slip the little nugget of information that he'd imprinted his personal data in the production of all Next Generation Reploids, effectively creating hundreds of Sigmas who would carry on his will whether they realized it or not.
• Neck Lift: In The Day of Sigma OVA, he does this twice, to Zero and then X. Also, during the boss fight with him in X8, he'll do this with one of your characters until you call for help.
• Nice Job Breaking It, Hero:
  • Begun with the very first game, at that. Downplayed in that Sigma was by and large the single most powerful Reploid in existence at the time, he had to be stopped and X was the only one who could do it, but destroying Sigma's body unwittingly just set him free, unleashing him in his true form, whereupon he understood just what he now was and what was well within his power to achieve.
  • The first part of the Evil Plan in X5, where Sigma baits X and Zero into fighting and defeating him at the beginning of the game, spreading The Virus all over the earth. One should know that it's a trap, since your Arch-Enemy wouldn't have let himself get beaten that easily.
  • In a bizarre twist earlier in the series, Sigma's battle with Zero pre-X. Sigma's actually The Hero in this scenario, and the whole battle (possibly when Sigma punches Zero's helmet crystal) was the cause of The Virus passing onto him, triggering his Face–Heel Turn and, in turn, Zero's Heel–Face Turn. Although, it could be that Sigma as a Maverick would be preferable to Zero remaining a Maverick.
• Nice Job Fixing It, Villain: Happens twice with Zero — one detailed in "Nice Job Breaking It, Hero" above, and another when he had the X-Hunters rebuild Zero after he was destroyed in the first game.
  • Sigma debatably does it a third time with Zero in X5. Interested in Zero's potential thanks to the information imparted to him by Wily about Zero's origins, Sigma spends his time trying to re-awaken Zero's Maverick programming and turn him against X instead of outright killing either of them from the beginning. X and Zero do end up clashing due to mistrust caused by Zero's connection to the Sigma Virus, but Sigma underestimates the strength of their bond, with Zero going on to protect X from Sigma's sneak attack and deliver the final blow to Sigma.
  • To a lesser extent, he does this to X in the OVA. After he taunts X by strangling Zero in front of him to make him a Reploid-shield and telling X to try to shoot him (knowing that X would hesitate), then gored Zero and throw him away, and then gored X himself, X goes into a brief shutdown but then snaps, and claws Sigma with his glowing hand, causing the trademark scars. It also triggered X's Character Development.
  • Forcing Eurasia into a Colony Drop on the Earth would have a major miracle that would pay off a century after his death, since its environmental control system that survived his scheme to awaken Zero's true loyalties and spreading the Sigma Virus on a global scale brought nature back to an area that was once barren, making it a viable alternative for humans compared to Neo Arcadia during the events of Mega Man Zero 4.
• Ninja Pirate Zombie Robot: His One-Winged Angel in X1 is a wolf robot (and technically zombie too), while his first form in X4 is a Grim Reaper robot. In X6, one of his forms is a robot zombie.
• No-Holds-Barred Beatdown: On the receiving end of this trope back when he was still the Commander of the Maverick Hunters, courtesy of Zero.
• Not Me This Time: Zig-zagged in X6. While Gate was the mastermind behind the "Nightmare" incidents, the whole reason he turned heel in the first place was because of the Sigma Virus! This may also account for why he resurrected Sigma in the first place, even if the resurrection was completely botched.
• Oh, Crap!: Pre-infection, after Zero rips off his arm where he holds his saber, he is shown to be visibly terrified as the Maverick slowly (and menacingly) walks towards him to deliver a viciously sadistic beatdown. And a dream sequence, seen twice in cutscenes, reveals that he is practically screaming for his life.
• Omnicidal Maniac: As his sanity withers away and his grudge against the heroes grows, his plans become more destructive and extreme. He goes from wanting to create a world for Reploids (X1), to taking over the world (X3), to simply destroying it outright (X4—X8). Considering why he went rogue and who made the Maverick Virus, it's easy to guess the cause of this.
• One-Winged Angel: In every game except X8 Sigma is first fought in his humanoid body before moving into a bigger, nastier battle form. A recurring motif of these forms is that Sigma’s humanoid face is usually visible in some way, and tends to be the only place he can be damaged.
• O.O.C. Is Serious Business: Sigma is a violent, mindless monster in X6 due to an incomplete resurrection. It shows just how far he's fallen from grace, and how insane Gate was to try resurrecting him at all.
  • Sigma sputters in disbelief after his ultimate defeat in X8, unlike other games where he accepted the loss and assured he would return. This implies that he was well aware this was his final act.
• The Paragon Always Rebels: He was a honorable commander of Maverick Hunters before he became a Maverick leader.
• Playing with Fire: His final form in X1 and his first form in X3 both have fire based attacks. His final phase in X4 has three robotic heads with the elements of fire, ice and lightning.
• The Power of Hate: Somewhere along the way, Sigma's continued thwarting by the Maverick Hunters began to strike a sour note, though Sigma usually manages to hide it well. He revels in the fact that, prior to X5, he met an interesting character (i.e. Wily) who hated X as much as he did, and his zombie form in X6 does little more than howl in remembrance of his hatred for X and Zero.
• Pragmatic Villainy: Disapproves of Berkana's actions from Xtreme 2, because she acted for her own gain (rather than his).
• The Professor: He uses this title as an alias in X7.
• Promoted to Playable: After almost 30 years since his debut, Sigma finally gets to be playable in DiVE as of July 1st, 2020.
  • Meaningful Release Date: This date was not as random as it seems, other than rounding out a new month with a new character. According to the PC port's manual, the Day of Sigma took place in early July.
  • MvCI was also his first overall playable appearance, predating his playability in his home series by a few years.
• Properly Paranoid: When trying to convince General to go maverick, he explains that humanity intends to destroy any Reploid that doesn't obey them perfectly. Come the Zero series, and especially with the character of Dr. Weil, and it shows that Sigma was pretty much spot on with his assessment. Ironically, this was probably due to Reploids constantly rebelling at the slightest provocation. Often due to viruses. Which he spread.
• Punch! Punch! Punch! Uh Oh...: In a flashback scene in X4, Sigma fights Zero and seems to be getting the upper hand, until Zero cuts off Sigma's arm before beating him into a pulp. Sigma only wins when Zero's head crystal suddenly glows and gives him a headache, allowing Sigma to knock out Zero with a punch.
• Rage Quit: His entire plan in X8 is him relocating himself and New Gen Reploids to the moon, due to the earth being torn apart after so many prolonged wars, and then he's going to demolish the earth outright to start anew.
• Right-Hand Attack Dog: At the end of X1, he sics his robot pet Velguarder on X before confronting him personally.
• Sadist: Has some shades of this when taunting Zero about Iris' death.
• Rouge Angles of Satin: This happens when Sigma enters his final phase in Mega Man X6, with many of his words being misspelled. Examples include "battle" > "baddle", "just" > "jusd", "begun" > "begunn", and "Just die!!!" > "Jusdie!!!"
• Sanity Slippage: With each subsequent game and each subsequent resurrection, Sigma's sanity began to gradually erode. Over the course of the series, he goes from a charismatic, sophisticated Diabolical Mastermind to little more than a brutish thug driven only by his hatred for the heroes, but retaining enough of his intelligence to be extremely dangerous. One can probably guess why his sanity was degrading, merging with a virus made by a insane mad scientist and then spending a lot of time jumping between bodies and hanging out outside of a body, nevermind the whole Hive Mind thing that comes with being a virus, probably did not do wonders for his mental state.
• Scars Are Forever: No matter what body he uses, the trademark scars over his eyes are left intact. Even when he gets entirely new bodies with new heads, he always retains these scars as a sort of trademark. How he obtained them varies between continuities: a flashback in X4 attributes the scars to battle damage from Maverick Zero's No-Holds-Barred Beatdown, while the The Day of Σ shows X scratching Sigma over the eyes with a Shining Finger-like attack, and both the Iwamoto Yoshihiro manga as well as the novelization for X1 has him scar himself with the heat from his cannons as he wages war against humanity.
• Secondary Color Nemesis: Best seen in official artwork, but his standard outfit consists of a green body armor with purple sleeves and pants.
• Self-Fulfilling Prophecy: Sigma predicts that humanity will scrap any Reploid that doesn't obey them perfectly, so he launches numerous genocidal campaigns against the humans. Even if Sigma might be right, as shown in the Zero series, what he did definitely contributed to his prediction.
• Shadowed Face, Glowing Eyes: Sigma's first form in X4 has a pretty clear parallel to the grim reaper, with glowing yellow eyes from a face hidden by a dark cloak, while also floating and carrying around a huge scythe.
• Shock and Awe: His final form in X1 and his first form in X2 both make use of thunder-based attacks. In X4, one of his final phase's moves involves three heads with the powers of fire, ice and lightning.
• Shotguns Are Just Better: His main weapon in X7 is a double-barreled shotgun.
• Signature Laugh: "Hee Hee Hee!"
• Sinister Scythe: Trades in his trademark Laser Blade for one of these in X4 to go with his overall Grim Reaper motif.
• Slasher Smile: He seems to always have a manic grin on his face.
• Slouch of Villainy: He does this in X8.
• The Sociopath: Thanks to the Maverick Virus, Sigma went from a noble-hearted Maverick Hunter to a ruthless monster who manipulates other Reploids into doing what he wants, kills countless innocent people, and sadistically terrorizes X and Zero time and time again. He's even more of a sociopath in Maverick Hunter X because he chose to become evil, and didn't need to be infected with a virus to go Maverick.
• Spanner in the Works: Unwittingly defeats Wily's plan to have Zero wreck havoc on the world, in the process setting up Zero's Heel–Face Turn. However, it also leads to Sigma's own turn. In X5, it's implied that Wily (whose somehow still around) uses this to his advantage and upgrades Sigma instead)
• Spikes of Villainy: Added these to his armor after his Face–Heel Turn. They frequently adorn his armor in his later incarnations.
• Taking You with Me: He tries to take both Zero and X down with him in X5 before Zero fires one last shot, completely destroying him. Sigma half-succeeded; he did mortally wound X, but X is then repaired by Dr. Light afterwards.
• This Cannot Be!: At the end of X1:
  Sigma: No!!! It's not possible! I'm a Reploid! I can't be destroyed by you! Why, X?! Why have you done this us?! Without the humans, my Reploid brothers could have ushered in a new age...
• Throwing Your Shield Always Works: Sigma in X3 throws his shield like a boomerang once his health gets low enough.
• Took a Level in Dumbass: In X6, to the point where he speaks in broken dialogue, and in X8, where he's being used by Lumine.
• Typhoid Mary: At some point Sigma bonds with the Maverick virus and becomes a living virus himself. He even exploits this in X5, sacrificing one of his bodies in order to infect the entire world.
• The Unfettered: He'll do whatever it takes to ensure the extinction of humanity comes to fruition, and doesn't give a damn about the consequences of his actions.
• Unexplained Recovery: Subverted for most of his reappearances besides X4. There is literally no explanation for his recovery here, though some fans believe it's a carry-over of his resurrection in Xtreme 2 by Berkana.
• Unfinished, Untested, Used Anyway: A recurring problem Sigma suffers from is that several of his awe-inspiring One-Winged Angel forms aren't actually finished being constructed yet, most notably in X5 where he outright admits it's not ready despite Dr. Wily's work, and some of the ones that are haven't even been put through their paces in testing like in X3. But X/Zero envitably always blow up his humanoid form for the day before then, so might as well break it in (and break it down) against the best.
• Unwitting Pawn: If Lumine's words are to be believed, Sigma was actually being used by Lumine in X8, particularly with the plan to migrate to the moon using the Jakob Orbital Elevator. Played with in that it's confusing about who's using who; while Lumine might be right, he still has Sigma's DNA put into his Copy Chip, and thus possesses Sigma's will and plans; basically Lumine keeps furthering Sigma's plan, even if he still retains his individuality, including making Sigma his pawn.
• Villain Decay: Invoked. After Sigma truly died in X5, his botched resurrection by Gate led to Sigma steadily losing his own villainy more and more. By the time X8 rolls around, he's completely abandoned his own mission and decides to just wipe out the Earth and start his own society on the moon, a plan so rife with holes that you know all ability to rationalize has left him. It doesn't go unnoticed, either. Starting with X6, X and Zero no longer regard Sigma as any kind of Worthy Opponent, and only seem to consider him a threat from little beyond his destructive potential if left to his own devices.
• Villain Opening Scene:
  • In the opening cutscene of X's X4 story, a cloaked Sigma is having a discussion with General about the Maverick Hunters, trying to convince him to fight against and destroy them.
  • In the opening cutscene of X5, Sigma has a discussion with Dynamo to spread The Virus across Earth.
• Villain Takes an Interest: In X4 after taking down Maverick Zero, Sigma orders his troops to retrieve him so he could study Zero. Maverick Hunter X has him intrigued by the limitless potential X possesses, believing it would be the key to Reploid evolution.
• The Virus: His true form, after the Maverick Virus from Zero's Capsule merged with him. According to Mega Man Zero Official Complete Works the true form of the Sigma Virus is the Suffering Circuit (it implies that Dr. Wily has stolen the data of said circuit from Dr. Light), which gives X and all the Reploids the ability to decide right and wrong for themselves; the virus corrupted both his DNA and said Suffering Circuit, creating a new virus strand that is alive with his consciousness.
• Wave-Motion Gun: Uses giant laser cannons in several of his battles such as X3, X6, and X7.
• Weakened by the Light: In X8, his real body is weak against Optic Sunflower's light-based weapons. Definitely symbolic.
• Weaksauce Weakness: His One-Winged Angel forms tend to suffer this in one way or another. Worst possible contender? Splash Laser, a literal Bubble Gun.
• Weak to Fire: His cloaked reaper form in X4 can only be harmed by the fire-based weapons obtained from Magma Dragoon, nothing else will harm him. A Logical Weakness considering that his cloak burns and catches on fire when he's hit by fire weapons.
• Well-Intentioned Extremist: He started off as this in the first game, where he wanted to remove humans from the equation out of a genuine desire to allow Reploids to grow and evolve while realizing their true potential before devolving into a murderous lunatic in the later games.
• While Rome Burns: At the end of The Day of Sigma, he eagerly awaits X to reach him while evilly laughing as Abel City is devastated by his missiles.
• World's Strongest Man: At the time of his creation, Sigma was the most advanced and powerful Reploid produced, befitting his position as the to-be leader of the Maverick Hunters (meaning he would be the last line of defense against any Maverick) and equipped with the most advanced anti-virus systems of the day. He could even fight on par with an Ax-Crazy Zero, and with X still deep in his Reluctant Warrior phase and Zero losing some of his lethality after going sane, Sigma was essentially the most powerful being on the planet. Sigma only lost this title as X grew into his true power while Sigma began to fall into Villain Decay from repeated defeats and deaths.
• Wolverine Claws: Uses Laser Blade variants as his weapon for X2 and Xtreme 2.
• Worthy Opponent: Though both the main protagonists would be loathe to admit it, the one thing about Sigma nobody dared to ever underestimate of the Maverick commander in the main pentalogy was his raw power and combat skill, and he is perhaps the only character to consistently be a match for X and Zero. Even as far as X8, his form is acknowledged as more or less the the most sturdy and powerful form a New Gen Reploid could take to avoid harm.
• You're Insane!: Called this by Vile in Maverick Hunter X for planning to take advantage of X's potential upon starting his rebellion.