Sigma

is a major character and antagonist in the X era, serving as the final boss of most Mega Man X games. He is a highly-advanced Reploid who was originally built by Dr. Cain to lead the Maverick Hunters, but he developed a hatred for humans and threatened to take over the world. To make matters worse, his mind transformed into the Sigma Virus, a form in which he survived throughout the series even as his body was destroyed.
Though Sigma assumes different forms throughout the series, he always retains iconic features such as his bald head, glowing eyes, and a muscular figure with green and/or purple armor.
==In the Games==
===Mega Man X===
Sigma debuted in Mega Man X, where his backstory is described in the game's manual. Sigma was created by Dr. Cain to lead the Maverick Hunters. He was Cain's magnum opus, touted as the most powerful and intelligent Reploid of all time. He was given a prestigious SA rank and personally took charge of the 17th Elite Unit.Game manual, Rockman X. December 1993. He initially took his post on March 16th, 20XX, effectively leading the Maverick Hunters for at least four months. On June 4th, 20XX, Sigma suddenly went Maverick himself, having secretly organized an anti-human rebellion using the Maverick Hunters as his army.The dates after November 22nd differ in the Japanese version of "The Journal of Dr. Cain", being on average a month or two later than the dates in the English version. Additionally, it says Sigma led the Hunters for two years with no issues, while the English version only indicates four months. This is the inciting incident of the game, forcing righteous Hunters such as X and Zero to go up against him and their former comrades to save humanity.
Sigma is only seen in-game once all eight Mavericks on the Stage Select screen are defeated, when Sigma's portrait appears in the center of the screen. X does not encounter Sigma until , the final stage. After X climbs a tower, Sigma teleports in and gloats that he could easily destroy X, but will leave him to his pet, Velguarder. Once X defeats it, Sigma returns and applauds his strength before discarding his cloak to face him with a beam saber. Once Sigma is defeated in this form, his body is destroyed and only his head remains, which ascends into a giant wolf-like robot in the background: Wolf Sigma. When X is once again victorious and the robot begins to explode, Sigma cries out in disbelief and asks X why he fights against Reploids. X flees, leaving Sigma to apparently perish.
After the credits roll, Sigma's face reappears on a monitor, revealing that X only succeeded in destroying his body and that his "spirit" remains intact. He threatens to return in other bodies to continue his plans.
===Mega Man X2===
===Mega Man X3===
===Mega Man X4===
A flashback in Mega Man X4 shows Sigma's past leading the Maverick Hunters. When Sigma learned that the berserk Zero had destroyed Garma's unit, he went to face the mysterious Maverick himself. He was overpowered by Zero in the ensuing battle, until Zero was suddenly immobilized by a great pain: the Maverick Virus taking hold."There Were Originally 24 Maverick Hunter Units, and Other Mega Man X Tidbits (Updated)", The Mega Man Network. Feb. 12, 2018. Sigma took the chance to punch Zero's head and defeat him. He then ordered the Maverick Hunters to take Zero back for study, while he limped away for repairs. However, Sigma was unaware that he too was affected by the Maverick Virus, and in the following period of time it began influencing his thoughts towards rebellion against the humans.
== Behind the Scenes ==
=== Creation ===
Keiji Inafune originally designed three separate characters — a tall one, a short one, and a fat one — to act as a triumvirate of villains for Mega Man X. However, they were eventually merged into a single character, Sigma (the idea of three villains was later reused for the X-Hunters in Mega Man X2). His mark was originally a cobra with a "W" shape in its hood to foreshadow Sigma's connection to Dr. Wily, though it was eventually changed to a wolf with a "Σ" shape in its jaws instead. The uppercase sigma was intentionally chosen for its resemblance to a W rotated ninety degrees.
=== Nomenclature ===
Language	Name	Origin
Japanese	 	Named after the Greek letter sigma (uppercase Σ, lowercase σ), which is used as the mathematical notation for summation. This may refer to Sigma's reputation as the most powerful Reploid of all time, the sum of all Reploid technology. An uppercase sigma (Σ) is also used as the symbol for Mavericks throughout the X era.
English 	 	Named after the Greek letter sigma (uppercase Σ, lowercase σ), which is used as the mathematical notation for summation. This may refer to Sigma's reputation as the most powerful Reploid of all time, the sum of all Reploid technology. An uppercase sigma (Σ) is also used as the symbol for Mavericks throughout the X era.
== Notes ==
==References==
Category:X era characters
Category:Marvel vs. Capcom: Infinite fighters
Category:Mega Man X DiVE characters
Category:Animated series characters
Category:Maverick Hunters