Zero/Maverick Hunter X

Zero (ゼロ) is the deuteragonist of Mega Man Maverick Hunter X. An A-Class Hunter in the 17th Elite Unit of the Maverick Hunters, Zero is the best friend of X, mentoring him as the hesitant B-Class Hunter struggles to bring out his potential.

The Day of Σ
Zero and the 17th Elite Unit were dispatched to deal with a Maverick Mechaniloid wreaking havoc in Abel City. He watched proudly as X arrived on the scene via airdrop and hit the Mechaniloid with a Charge Shot, though it didn't do much. After the Mechaniloid retaliated, Zero fired a shot that damaged its leg and hampered its mobility. X tried to shoot the Mechaniloid's generator, but took too long, so Sigma went in for the kill and slashed it with his saber. After Chill Penguin and Sigma both lectured X for his hesitation, Zero comforted him with a hand on the shoulder.

Back at Hunter Base, Zero and X discussed what could cause someone to go Maverick. As if on cue, they watched as the arrested Vile was taken to a cell for some sort of violent incident. Later, Zero entered virtual reality training to practice his shooting against the same Mechaniloid from earlier that morning. He missed the shot, scoring 95% total in the test. Storm Eagle then appeared, congratulating him on the grade and bringing him to a briefing involving the recent Maverick incidents.

At the briefing, Zero was surprised by how close to Hunter Base the Maverick signals were located. X and Zero went to investigate, finding several murdered Mavericks and computers with their data wiped. Zero noted the accuracy of the slash marks on the Mavericks, and a hunt for the perpetrator began.

Even more Mechaniloids went berserk the next day, so Zero and X were dispatched. However, they were suddenly called back to Hunter Base to investigate Vile's mysterious escape from his cell. Zero again noted the efficiency of the strikes on the guards. Before he could think much longer, he and X were again redirected, this time to investigate the missile base on the outskirts of Abel City.

At the missile base, Zero and X found Sigma at a computer. Zero quickly realized that Sigma was the one responsible for the Maverick incidents, so he was able to defend against his strike from behind. However, Sigma quickly gained the upper hand and held Zero in the air, urging X to try saving him. X hesitated yet again out of fear of hitting Zero, so Sigma slashed Zero with his saber and threw him to the ground. Because of the injury, Zero remained out of commission while Sigma fired the missiles at Abel City and continued to punish X.

Once Zero woke up, he found X damaged and disabled, causing him to let out an anguished cry. He then carefully brought X back to Hunter Base for repairs.

X Mode
After Sigma's declaration of Reploid Independence on July 4 21XX, dubbed "The Day of Σ", Zero became the de facto leader of the Maverick Hunters due to being the highest-ranked Hunter at the time. While fighting the invasion of Abel City, he appeared just in time to save X from Vile's rage, forcing Vile to flee aboard the Death Rogumer. Afterwards, X thanked him for the help and the two split up again.

While X fought eight former Maverick Hunters in order to slow the rebellion, Zero continued to perform reconnaissance regarding Sigma's plans and the location of his new base of operations. Upon doing so, he sent a transmission to Hunter Base announcing the location and urging X to join him in raiding the fortress.

Zero and X both attacked the fortress from different angles, with Zero taking the brunt of the enemy fire for his friend. In the third segment of the Sigma Palace, Zero encountered Vile in an upgraded Ride Armor and was defeated by him. Vile then left the damaged Zero out in the open as bait. X took the bait and was ambushed, leaving him again at the mercy of Vile. However, Zero recovered enough strength to leap onto the back of Vile's Ride Armor, and overloaded his Zero Buster in order to completely destroy it. Unfortunately, he took heavy damage in the blast, forcing X to finish Vile off on his own.

After Vile's destruction, X rushed to Zero, who had been split in half at the waist by the explosion. Zero acknowledged the irony of always protecting X without being able to protect himself. If X didn't have the Arm Parts, Zero gave him his own and urged him to defeat Sigma before passing away. ).

Vile Mode
In the non-canon scenario Vile Mode, Zero played a role similar to the base game with some slight differences. After Vile defeated X for the first time, Zero instead grabbed X and warped back to Hunter Base with him instead of fighting Vile off.

Zero reappeared in the third portion of the Sigma Palace alongside X, who had equipped his full First Armor. They cornered Vile together in order to stop his rampage, surprised that he wasn't in fact working for Sigma, resulting in a simultaneous two-on-one battle. Zero ended up severely injured by Vile, who gained the upper hand over the pair and began abusing X. Zero took the opportunity to sneak up and grab Vile's leg, holding him in place so X could finish him with a Charge Shot. It is unknown if Zero managed to survive the Charge Shot that critically wounded Vile, or if, like in the main game, Zero also ended up destroyed in a sacrificial effort to help bring Vile down.