Zero (voiced by Lucas Gilbertson and Johnny Young Bosch) is the secondary hero in the Mega Man X series and the main hero in the Mega Man Zero series. He's armed with a sword called the Z-Saber and a gun called the Z-Blaster. He's a loyal friend and partner of Mega Man X.
Mega Man X Saga:
Zero was made by Dr. Albert Wily, Dr. Light's rival. He was first activated as a Maverick, but he later joined the Maverick Hunters due it not having any Maverick behaviors. After a series of murders, he along with X track down their leader Sigma to a missile silo where Sigma reveled his true colors: to destroy mankind. This was caused by a virus from Zero which unknown to him was created by Dr. Wily himself. He wounded X and knocked Zero out cold. When Zero came do, he dragged the wounded X to safety. Zero help X to defeat one of Sigma's men, Vile, by sacrificing himself. He reappear 6 months later and destroy his clone self. Zero have fought and defeated the Colonel who have betrayed the Hunters by joining Sigma. Zero volunteer to fly a shuttle to the space colony Eurasia in order to destroy it before it crashed to Earth. Zero survived, but tired. Awaken, Zero meet up with X inside Eurasia to find clues about the virus called the Zero Virus. Zero and X are forced to fight each other. X beat Zero, but lost conciseness. Zero came to, he once again, encountered Sigma. He manage to drove Sigma back. For now. Zero vow to defeat Sigma once and for all. Later, X found Zero, barley alive and his lower body missing. Sigma blast through both him and X. In an act of heroism, Zero used the last of his energy to destroy Sigma. 3 week later, X and his team rebuild Zero. After defeating Sigma one last time, Zero was put into stasis in order to remove a component from his body before saying farewell to X and his comrades.
Mega Man Zero Saga:
100 years later, Zero was reawaken by a scientist named Ciel who was chased to a underground lab. He was brought to a world were Reploids are accused of being Mavericks and are murdered. Zero joined the resistance and fought X's clone, Copy X. He meet he's former partner, now a spirit, he grow tired of fighting and without a physical body, he leave the protection of Earth to Zero and vanish. A year later, Zero was founded by Harpuia. One of the Guardian Four. Zero was delivered to the resistance and was repaired. He discovered that a reploid named Elpizo lead the resistance who plain to launch a full scale attack on Neo Arcadia, but the attack failed, leaving Elpizo the only survivor. Driven mad, Elpizo seek the Dark Elf, which brought about the Elf Wars 100 years back. Zero manage to find Elpizo in a chamber that holds his partner's original body. Despite Zero and the Guardians (Who agree to help Zero) best effort, Elpizo destroyed X's body and unleashed the Dark Elf. Zero defeated Elpizo and the Dark Elf turn him into a Cyber Elf, and revealed to Zero that she's not truly evil at all. Mega Man X appear to Zero and told him that the Dark Elf was once a savior, until Zero's creator, Dr Wily, cursed her. Two months later, Zero and the resistance discovered a crashed ship which was giving out the same kind of energy reading as the Dark Elf. Zero when inside the ship to investigate and what he found Leviathan and Fefnir, two members of the Guardian Four fighting a giant reploid named Omega. Zero interfere and fight. It was interrupted by Dr. Weil, who was banished from Neo Arcadia 100 years ago along with Omega, and somehow survived. Dr Weil rebuild Copy X who was defeated a year ago. Later, Dr. Weil double-crossed Copy X, and destroy him. After Zero fight and defeated both Omega and Dr. Weli, zero broke the cursed placed on the Dark Elf and changed into her true form, Mother Elf. Despite this lose, Dr. Weli became the new ruler of Neo Arcadia. The people will soon learn on his wraith. After this, many left Neo Arcadia. Zero saved a caravan that was attacked by Dr. Weli's troops. Zero, along with Ciel meet Neige, a former journalist. Neige explain to them that the humans are going to a settlement in Area 0, a place that is safe from Dr. Weli and his soldiers. Zero later figure out that Dr. Weli have a massive orbital cannon called, Radnorox, which have the firepower to obliterate a entire city with a single blast. In a selfless act of bravery and sacrifice, Zero defeated Dr. Weil and drive Radnorox into Earth's atmosphere which broke into many pieces. Zero's fate remind unclear.
Zero will meet Aaron and his team in Aaron's meet Mega Man X and Mega Man Zero series.