Sigma PXZ2

Original Appearance:

Mega Man X



Voice Actor:


"It's not over yet, X! The battle! The angst! The destruction! I will make you understand the true potential of Reploids!"
—Sigma as a Maverick, Mega Man Maverick Hunter X

Sigma (シグマ?) is the main antagonist of the Mega Man X series and a Boss unit in Project X Zone 2. The strongest Reploid 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.



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. Sigma then left to confront it alone, in order to prevent other Reploids' deaths at the hands of the Maverick. It is here that Sigma encountered Zero, the last product of Dr. Wily. Zero, having suffered a programming flaw from his creation, was uncontrollable, unleashing wanton destruction wherever he went. Sigma was beaten badly by the maddened Zero, but managed to smash the energy crystal in Zero's helmet. The fight, due to taking place in close proximity to Zero's capsule, which was leaking trace amounts of the Maverick Virus, and the damage they already sustained in the battle, transferred the Maverick Virus directly into Sigma and Zero, infecting them. Zero lost consciousness, and Sigma limped away from the battle, ordering his men to take the body of Zero back for study. The virus had different effects on them: Although the virus corrected the flawed programming in Zero, it began to mutate and adapt to Sigma's own programming, eventually fusing entirely with his mind to form the Sigma Virus, which allowed him to manipulate and control Reploids, bending them to his will. After this, he began to feel that humanity was keeping Reploid potential down, and decided to revolt against humanity.

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, which is Sigma's real intention. Fortunately, Mega Man 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. In order to ensure both sides of the war were manipulated, he also had one of his agents, Double, infiltrate the ranks of the Maverick Hunters, and also seduced Magma Dragoon with the concept of power and a chance to fight X/Zero in exchange for instigating the war. He also had Cyber Peacock and Split Mushroom fight against X/Zero to test their power and capabilities. Eventually, he had Double fight X when he infiltrated the Final Weapon, and also ordered him to kill some members of the 17th Unit of the Maverick Hunters as their presence risked compromising Sigma's plans.

Project X Zone 2Edit

Sigma was revived by Vile MK-2 to help him bring misery to X and Zero.

Crosspedia EntryEdit

PXZ2 Sigma

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. 


  • Gear: Shoulder Boomerang
  • Accessory: None


Chapter 27 256840067423013717530335
Chapter 31
Chapter 34
Chapter 37
Final Chapter

Attacks Edit

Name Strength Target Effect
Attack A None
Special: Reaper's Scythe S 1 Unit None
MA: Reaper's Lightning S 2-4 Units None

Auto Skills Edit

Name Effect
Nullify Poison Cannot be poisoned (or removes the effect)
XP Counter Reduces foe's XP (EP) by 1% of incurred damage


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