Sigma

Personality: Sigma started his career as a noble warrior who only desired to accomplish his tasks and keep peace by destroying the mavericks, but once the virus took over him and corrupted his programming, Sigma progressively became a monster, hell-bent in eliminating humanity. Sigma has an interesting trait that sets him apart from the other villains in the Megaman X series. While most other Reploids lose control of their inhibitions and conscious though, and, for lack of a better term, go insane, Sigma does not. He is able to study and learn new things, such as the reasoning for X's constant worry, Zero's shady past, among other things. He is even able to conceptualize grand-scale plans and effectively strategize while in this state. With most infected Mavericks, we never see their true personality, as it is masked by the virus. However, Sigma shows his true personality all throughout. He is a bossy, brilliant, and destructive military strategist who uses this to his full advantage. He allows his right hand man, Vile to whatever he wants for his own accords. His obsession with destroying humanity as well as X and Zero stems from the virus, but one thing that has always set Sigma apart is that he doesn't lose control of himself. Sigma has always been very discerning, intelligent, perspicacious, and imaginative, and remains so. He keeps his enemies' weaknesses in mind and preys on them (such as X's big heart, Zero's wanting to block out all mention of his bloody past, or Axl's discontent at being called a prototype). Sigma's personality itself, post-infection, has been very manipulative, ruthless, power-hungry, and sadistic. He controlled Dr. Doppler into distributing a placebo antivirus which was instead the virus, manipulated the Colonel and the General of the Repliforce (a military-like group meant to compliment the Maverick Hunters) into a full-scale war, and Blackmailed the leader of the mercenary Maverick hunting group Red Alert, Red with his infected and mind controlled friends into cooperating with him in fighting the Hunters.

Appearance: Although Sigma has taken many diverse forms throughout the series, his designs retain several consistent traits. His face is arguably more anthropomorphic than even X or Zero, possessing a bald human head with a gem in his forehead and a cleft chin. His eyes are bright blue or white, possessing no irises or pupils, and with a scar torn over each eye. His tall and bulky frame resembles a muscular human body, and his color schemes always include green and/or purple.

Abilities: As the former commander of the Maverick Hunters, Sigma is a capable military leader, described as possessing overwhelming combat power and strategic intelligence. His circuitry is the most advanced of its time, which allowed him to maintain a semblance of sanity even while mutating with the Maverick Virus. When he finally gave in and turned Maverick, Sigma remained a charismatic leader. If his wiles are not enough to sway one's mind, he is also able to infect them with the Sigma Virus to force them into madness and loyalty. Due to his affinity with said virus, Sigma's "spirit" can also survive seemingly any physical damage that would be lethal for other Reploids. It is undetectable by conventional scanners, and can only be sensed by Reploids. Its intangibility also allows it to ignore physical assaults and energy attacks, except for those tuned with a Virus Buster or Dr. Doppler's vaccine. When not in his viral form, Sigma always has the most physically-advanced and variable Reploid bodies available at the time. He possesses incredible strength and speed, often able to move faster than the Maverick Hunters can follow, and is usually capable of teleportation. In his first body, during a conflict with the Maverick Zero, he was able to effortlessly break through Zero's defenses with a round kick, as well as easily toss him through the ceiling with a single arm. He is also fond of incorporating himself into a variety of battle bodies, each possessing widely different arsenals. He is a capable warrior regardless of whatever weapon he wields, whether it be a beam saber, beam claws, or a shield. In nearly every appearance, Sigma is capable of discharging enormous destructive blasts or waves of power capable of covering entire battle areas, and he is a skilled marksman. As the cause of death and suffering for countless innocent lives, Sigma is one of the most dangerous villains in the classic Mega Man universe.

Beam Saber: Sigma rushes forwards and slashes once with his beam saber. Triangle Kick: Sigma leaps from wall to wall in a triangular motion. Machine Gun: Sigma shoots five projectiles from his forehead. Claw Attack: Sigma rushes forwards and slashes with a claw. Aerial Claw Attack: Sigma jumps off the wall and disappears, then reappears above the player with a diving claw attack. Five Bullet Shot: Sigma summons five lightning balls that sequentially fly in the player's direction. Electromagnetic Wave: Sigma charges up, briefly becoming invincible, before throwing a wall of electricity from both claws. Flame Shot: Sigma jumps into the air and shoots three fireballs at the floor, each splitting along the floor and walls. Rapid Fire Flame Shot: Sigma shoots a sequence of six fireballs with a variety of trajectories, each climbing the wall on contact. Shield Throw: Sigma throws his shield, which returns to him like a boomerang. If the player is above him, Sigma throws the shield upwards so it moves in a figure-eight shape. Shot Attack: Sigma releases projectiles which either drop to the floor and spread outwards, or immediately spread out before crossing the floor. Scythe Attack: Every third time Sigma appears, he swipes across the arena with his scythe held below. He is invincible to everything when performing this attack. Scythe Throw: Sigma jumps and throws his unlit scythe in a circle around himself. Laser Attack: Sigma throws his scythe directly at the player. The scythe then sticks into the surface it hits, emitting electric charges as long as it stays there. Boomerang Attack: If Laser Attack charges the floor, Sigma ejects four boomerangs from his shoulders that sequentially chase the player, staying in place midair. Laser Eye: If Laser Attack charges a wall, Sigma leaps to the other side of the arena and fires eye lasers diagonally across the floor. He holds the lasers for a long time, but the entire wall behind him is safe.

He is the primary antagonist of the Megaman X series. He serves as the final boss in all mainline games in the series, except Megaman X8 where he is the penultimate boss in Normal and Hard mode. Once the noble leader of the Maverick Hunters, Sigma fell into insanity and turned Maverick himself, becoming the leader of all haywire Reploids and waging war on humanity. Although he has been destroyed countless times, Sigma's programming always survives and finds a new form, ready to menace the world once again.