Zero Buster

The Z-Buster (ゼットバスター) is one of Zero's main weapons in the Mega Man X series, appearing from Mega Man X to Mega Man X6.

In the first three games, the Z-Buster is a chargeable arm cannon embedded in Zero's arm(s) that is more powerful than the X-Buster, in Mega Man X being able do damage Vile's Ride Armor while X couldn't. If X didn't obtained the Arm Parts from the First Armor after defeating Vile in Sigma's hideout, Zero will give his arm cannon to X. In Mega Man X2 and Mega Man X3 Zero's Z-Busters can be linked to each other to fire two Charge Shots one after the other; however, they do not combine.

When Zero became a fully playable character in Mega Man X4, his Z-Buster was completely removed due to game balancing, but it was re-introduced in Mega Man X5; in this game, it was only usable if the game was started with Zero, as he loses it in his battle against Sigma Head if starting with X. However, the Z-Buster's usage was stripped down drastically. It could only be used on the ground, and Zero was unable to move while firing it because he had to "charge" the attack. When Zero was resurrected in Mega Man X6, his Z-Buster received new abilities again. The fire frequency of the Buster was vastly increased (yet still bound to the ground) and its power was increased as well, making it rather useful against most enemies and bosses. After this game, the Z-Buster was never used again. The Z-Buster has undergone two design changes throughout the series.

In the Mega Man Zero series the Z-Buster was replaced by the Buster Shot gun, which Zero took from the deceased Milan to protect Ciel. The Buster Shot was mistranslated as "Z Buster" in the first Mega Man Zero game, a mistake that was fixed in Mega Man Zero Collection.