When making edits to long standing statements or facts on the wiki, you MUST PROVIDE CREDIBLE SOURCES FOR YOUR CLAIMS. edits done without will be UNDONE, NO REASONS GIVEN. Please use the talk pages to provide these sources before editing!



Sigma is the main antagonist and final boss from Mega Man X5, the source of the story's disasters including scattering the Sigma Virus around Earth and the fall of Eurasia, with the Zero Space and Zero Virus appearing where it crashed. He serves as the boss of the Opening Stage, and also appears in the final Zero Space stage for a final battle with X or Zero.


Sigma Head[]

Main article: Sigma Head

Sigma takes the form of a giant head to battle the Maverick Hunters in the Opening Stage.

Psycho Sigma[]

After the battle between X and Zero, they go after Sigma, facing him in his new body, Psycho Sigma (サイコシグマ).[1] He initially wears a cape of energy tethers and shoulder plates, discarding it to battle. Psycho Sigma attacks with his speed and energy attacks. Once he loses half his health, he can also generate Sigma Viruses that rotate around his body to protect him. This form is weak to X's Tri-Thunder and Zero's E-Blade.

MMX5 Sigma1 DashTackle Dash Tackle (ダッシュ体当たり Dasshu Taiatari)[2]
Sigma dashes towards the player. If they are above him, he dashes between the walls as if wall kicking.
Damage: 9:12:15
MMX5 Sigma1 HellSpark Hell Spark (ヘルスパーク Heru Supāku)[2]
Sigma throws out two single sparks, followed by double sparks, which fluctuate across the arena.
Damage: 7:10:12
MMX5 Sigma1 HellBlade Hell Blade (ヘルブレイド Heru Burēdo)[2]
Sigma teleports to one side and throws three energy cutters across the arena, forcing the player to dodge high, low, or in the middle. He only uses this attack once he has lost 50% health.
Damage: 15:20:25

Final Sigma W[]


Second form

After his defeat, Sigma reappears with a gargantuan body called Final Sigma W (ファイナルシグマW).[3] It is incomplete, and although only the upper half is seen, it is still incredibly powerful. It is speculated that this body was made by Dr. Wily due to the W in the name and Sigma's monologue after his first form's defeat.[4][5] His hands can be stood upon or destroyed, but they return after a while. This form can only be damaged by hitting the red core on his forehead, and he can't be harmed when he takes a wireframe appearance. He is weak to X's Spike Ball and Zero's Twin Dream.

MMX5 Sigma2 MissilePunch Missile Punch (ミサイルパンチ Misairu Panchi)[6]
Sigma uses the rockets on his hands to punch at the player. The spikes deal contact damage, but if one crushes the player onto a surface it deals more damage. Furthermore, when Sigma is below 50% health he may attempt to crush the player between both fists.
Damage: 6:8:10 (contact), 8:8:10 (punch), 14:16:18 (double punch)
MMX5 Sigma2 ChargeShot Charge Shot (チャージショット Chāji Shotto)[6]
Sigma's hand reveals an eye in its palm to shoot a projectile resembling X's Plasma Charge Shot.
Damage: 6:8:10
MMX5 Sigma2 TrackerBullet Tracker Bullet (遠尾弾 Tōnō-dan)[6]
Rear-End Bomb[7]
Sigma plants four sparks from his eyes onto the floor, which then fly to the player's location twice before fading.
Damage: 6:8:10
MMX5 Sigma2 ThunderAttack Thunder Attack (サンダー攻撃 Sandā Kōgeki)[6]
Sigma's hand hovers above the player, firing streams of lightning downwards and slowly pursuing them. He only uses this attack once he's lost 50% health.
Damage: 9:12:15
MMX5 Sigma2 PurpleCubes Purple Cube Attack (紫キューブ攻撃 Murasaki Kyūbu Kōgeki)[6]
Sigma materializes five purple cubes at the player's location; the fifth one stays longer, sliding around the arena after the player. He only uses this attack once he's lost 50% health.
Damage: 15:20:25

Slime Sigma[]

X5 scene 21

Slime Sigma

After his defeat, Sigma is reduced to "Slime Sigma" (スライムシグマ),[8] attempting one final attack on the Maverick Hunters. Sigma releases a beam from his mouth that pierces them both, but before falling, Zero finishes him with his Z-Buster. He is never directly fought in this form, due to it being a cutscene.

Damage Data Chart[]

X8NavigatorAlertIconEdit This section requires expansion.

Other appearances[]

Mega Man X DiVE Boss Final Sigma W

Final Sigma W in Mega Man X DiVE

Other media[]

Psycho Sigma appeared in Rockman X5 IF and Rockman X5.


  • This is one of two incarnations of Sigma to share his first boss background music with another portion of the game, the other being the the one from Mega Man X6. In this case, he shares the BGM theme with Sigma Head, and to a lesser extent the post-fight cutscene of said boss fight.
  • Except for some details, like the color of the ear parts, the design of Final Sigma W's head is the same as the Opening Stage boss, Sigma Head, the developers possibly using the same model for both bosses.



See also[]


  1. Mega Man X Legacy Collection 2's X Challenge mode
  2. 2.0 2.1 2.2 Boss File: Sigma (1st Form), Compendium of Rockman X. p. 86.
  3. </nowiki>Mega Man X Legacy Collection 2 Hunter Medals<nowiki>
  4. When playing as X:
    "Here I am. You can challenge me at anytime. I have delightful news. I've recently acquired a new partner. He has been very supportive. He seems to have created quite a few robots. And he gave me the toughest body that you will ever see. You got here sooner than I expected, so it is not yet complete... is enough to defeat you... He is an excellent partner... I believe you two know each other... In fact, he used to be a comrade of yours. He was very persistent about you... and that makes him very helpful to me. You see X, there is someone other than me...who hates you... Now feel our combined rage and die! ...But not before suffering horribly, hahaha! ...Goodbye, X!"
  5. When playing as Zero:
    "Hee hee hee hee. Calm down... I'm here. Let me tell you about an old man I met... He told me you are the strongest in the universe... Tell me, who is that old man? You should know him. Don't tell me you've never met him in your dreams. He seems very interested in you... as if he was your own father...!"
  6. 6.0 6.1 6.2 6.3 6.4 Boss File: Sigma (2nd Form), Compendium of Rockman X. p. 87.
  7. Mega Man X: Maverick Hunter's Field Guide. pg. 174.
  8. Description from the form's concept art.