This article is only about Sigma's participation in Mega Man X: Unit 49. To see Sigma's general information in the Mega Man franchise, click here.

Sigma as he appears
in Mega Man X8.
Comic Information
First Appearance None
Last Appearance None
Personal Information
Alternate Name Commander Sigma
The Professor
Birthplace: Dr. Cain's lab
Species: Reploid
Gender: Male
Age 20+ (November 22, 2170)
Death Several times, the last one being in 219X
Eye Color: Blue
Red (MMX8)
Combat Information
Primary Weapons: Σ Blade
Energy Manipulation: Sigma Virus
Unknown Energy (MMX8)
Affiliations and Positions
Enemies: Mega Man X (character)
Maverick Hunters

Sigma is the main antagonist of the Mega Man X series. He is the first Reploid created by Dr. Cain and also the first one to be appointed as leader of the Maverick Hunters, but defected to the Maverick side and became their leader in AD 2174. 

Sigma has been destroyed several times and remained alive as a virus, building himself new bodies and returning in a new form with more thirst for revenge and malignancy, except for the battle at the Moon during the Jakob's Incident period. Although Sigma is gone for good, his DNA is still implanted in the copy chips of every New Generation Reploid.

Saturn waited Sigma's death to raise his alliance with some of Sigma's followers (that are now without a leader) and also the criminals who never had any regard with him to start his huge plot against the Earth's Government and the Maverick Hunters and begin the Great Neo Maverick War. Although the two never had any allegiance, both leaders seek the evolution of the Reploids.

In the ending of Parade, Saturn refers Sigma as the "mate" of the mysterious man at his side, meaning they may have known each other in the past.

Mega Man X: Unit 49 Characters
Maverick Hunters

XZeroAxlSignasAliaLayerPalletteCaptain ElikaNoraPlatinaSnacmanBlue KnightRaikaRed ThunderFalsettoYingIllusionTricksterRondineRubre

Earth's Government

Alain • Cecil • Dunstan • Galdwin • Seymour • Raffould • Ihsan • Prabhu • Takahiro • Zhengsheng • Manfred • Ardashir


SigmaLumineSewer JailratCave BigratThe RatsMaestroDikho & Scatho

Neo Maverick Army

SaturnMysterious ManShadKranBaronelKerbekerosGigantexDoppelgangerCorrosive NagaxidCyclobbering OnimmerChaotic GargaleDevouriang ShiroidStriking CougaroidSnowhunt CoyoteSwift Kagecko


Dr. Henry SnacmanAkiraThe EngineersThe DealerDr. SeigenList of RaDoRB Characters