Zero

Zero (ゼロ) is one of the three main characters of the Mega Man X series, as well as the protagonist of the Mega Man Zero series and makes an appearance as Biometal Model Z in Mega Man ZX. In the X series, he is one of the highest ranking Maverick Hunters who is fighting to stop the endless war between humans and Mavericks, Reploids who either get infected by a virus and go berserk or have decided to rebel against humans on purpose.

Origin
Zero was created by the late Dr. Albert Wily somewhen in the 21st century. His first historical appearance was in form of shadowy blueprints during Bass' ending of Mega Man 2: The Power Fighters and described by Wily as his greatest masterpiece of work.

Originally designed to deal with Mega Man and Bass and to satisfy his creator's ambition of world domination, he was instead sealed away by Wily in order to carry out the objective of destroying Mega Man X and later awakened by a group of Reploids prior to the first Mega Man X game. When he was first activated, he awoke as a Maverick and destroyed all intruders who had dared to enter Wily's lair and was later cornered by Garma's Maverick Hunter unit inside an unknown facility, however at the cost of a total loss of said unit. Not wanting to get anymore comrades endangered by the powerful enigmatic Maverick, then-Hunter Commander Sigma himself challenged Zero in a one-on-one battle. Even though Zero gained the upper hand during the battle, Sigma was able to defeat the red Maverick after taking serious damage and knocked him out. He was then brought to Dr. Cain, who analyzed him.

After that, Zero recovered from his battle with Sigma and was placed under Sigma's witch, Zero did not show any signs of Maverick behaviour and was enlisted into the Maverick Hunters' 17th Elite Unit.

The Day of Σ
As part of the 17th Elite Unit, Zero became an excellent Maverick Hunter and was soon ranked SA-Class, the highest rank the Maverick Hunters had to offer at that point of time. It was during that time in which he met X for the first time who was also part of the 17th Unit, even though he was only ranked B-Class due to his hesistation on the battlefield. The two became friends and partners and worked together whenever they could. Zero soon became a somewhat mentor to X.

Soon afterwards, a series of Mechaniloids going berserk occured in Abel City, the city in which the Hunter Base at that point was located. During the course of the investigation, it was Zero who eventually uncovered the identity of the person responsible for the attacks, which was none other than Sigma himself. Zero had deducted this as in various locations which were seemly connected to the attacks, the bodies of defeated Reploids had been found which were all taken down with a single blow directed at a weak spot and there had been only a very few number of Reploids which such perfect skills, including Sigma. Also, the damage the defeated Reploids had taken was caused by a beamsaber and not by range-weapons so the previously suspected Vile couldn't have been the traitor.

Even though he managed to block Sigma's first attack, he was soon overwelmed by Sigma and was used to pressure X into surrendering. To get Zero out of his way, he was struck by Sigma's beam saber and left all by himself while Sigma held X captive and launched a missile attack on Abel City. Some time later, Zero regained concious and found X all alone in the facility, heavily damaged by Sigma. He then brought him back to the Hunter HQ.

Mega Man X / Maverick Hunter X
After Sigma's declaration of Reploid Independency on July 4th 21XX (June in the US manual of the original game), dubbed "The Day of Σ", Zero, at that point highest ranked member of the Hunter organisation, became the new leader and he and a repaired X fought together against Sigma's uprising rebellion. Zero saved X during a Maverick attack at the Central Highway from Vile. After that, the two split up with X task to slow down the Maverick activities in nearby areas while Zero himself was on recon duty at Sigma's fortess.

They eventually met there and together invaded the fortress. Here, they encountered Vile for a second time. Zero was captured by Vile and imprisoned in a cage (In Maverick Hunter X however, Zero was left unconcious by Vile as a bait for X). When X was also defeated by Vile, he managed to break free and destroyed Vile's armor by overloading his circuits, which was a successful, yet fatal action. Afterwards, Zero, in case X hadn't obtained the Buster Upgrade yet, handed his Buster Parts to X and encouraging him into continuing to fight before dying in X' arms.

Mega Man X2
After Sigma had been defeated, the Hunters tried to salvage whatever remained of Zero from the sunken fortress and found Zero's Control Chip (which serves as Zero's "brain" and conciousness) which had miraculously survived the destruction of the body. However, the Hunters were incapable of creating a new body for Zero because they were unable to analyze Zero's unique body structure.

Six months later, a group of three Mavericks, calling themselves the "X-Hunters" (Counter Hunters in Japanese), contacted the Maverick Hunters and claimed to be in possession of all parts of Zero. The X-Hunters challenged X to a battle in order to win Zero's remains. (The Japanese version of the game however claims that they actually rebuilt the parts and did not use remains from the previous game. It was Serges (Sagesse in Japanese) who constructed the parts and upgraded the body with the specs Zero was originally intended to have, including reinforced shoulder plates and Z-Saber).

X, who didn't want his friend to be in the hands of Mavericks, accepted and eventually recovered Zero's head, body and foot parts. Eventually, Zero was reconstructed by Dr. Cain (now completed with his signature Z-Saber and enforced shoulder plates) and assisted X in destroying the base of the resurrected Sigma. Trying to fool X however, Sigma had constructed a doppelgänger of Zero with Black Armor which he claimed to be Zero, however this copy was destroyed by the real Zero.

As a non-canon scenario in X2, in case X wasn't able to retrieve all of Zero's parts, the X-Hunters would steal any parts X had previously collected from the Hunter Base, as well as Zero's Control Chip. Zero would then be recontructed by Sigma as a Maverick and was fought by X prior to his encounter with Sigma. After being defeated, Zero would regain his consciousness and assisted in destroying the base.

Mega Man Xtreme
Under Construction

Mega Man X3
Under Construction

Mega Man Xtreme 2
Under Construction

Mega Man X5
Under Construction

Mega Man X6
Under Construction

Mega Man X7
Under Construction

Mega Man X8
Under Construction

Mega Man X Command Mission
Under Construction

Mega Man Zero
Under Construction

Mega Man ZX
Under Construction

Voice Acting
US:
 * Wayne Dozier (Mega Man X4)
 * Jack Merluzzi (Mega Man X7)
 * Lucas Gilbertson (Mega Man X8, Command Mission & Maverick Hunter X)

JP:
 * Ryotaro Okiayu (Complete X series)
 * Yuuto Kazama (Complete Zero series)

Trivia

 * Zero was originally intended to be the main protagonist of Mega Man X, according to Keiji Inafune, Mega Man's creator. However, Zero was turned into a second character because Inafune feared Zero's look would not be approved by fans as a true Mega Man. He would eventually gain his own game series on the GameBoy Advance, Mega Man Zero.