Proto Buster

Proto Buster, known as Blues Buster (ブルースバスター) in Japan, is the arm cannon in Proto Man's left arm, which was created by Dr. Wily. It's Proto Man's version of the Mega Buster, but unlike it, the Proto Buster lacks a transforming mechanism, being unable to change freely into the form of an arm like the Mega Buster can. However, Proto Man appears to be able to change his arm by other means, as he is seen with both arms in many instances, like Mega Man 7 and Mega Man: The Power Battle. The Proto Buster also consumes more energy than the Mega Buster, making it unusable for long periods of combat.

Appearances

 * In Mega Man: Powered Up the Proto Buster can only shoot fully charged shots, without Proto Man having to charge up, though his mode is barely canon.
 * In Mega Man 3 the Proto Buster shoots regular sized shots, much like Mega Man's shots.
 * In Mega Man 7, Proto Man shoot regular shots once more. However, his charged shots are much more devastating than Mega Man's, and they took the form of a giant green blast. He can also shot faster and in multiple directions.
 * In Mega Man & Bass, Proto Man used a charge shot against King in the first stage. Later in the game, Proto Man used the Big Bang Strike, which uses up most of his energy and destroyed King's shield.
 * In Mega Man 9 and Mega Man 10, the buster is only able to shoot two shots on screen and it is the only one able to shoot charged shots, more similar to Mega Man's charged shots in Mega Man 4.
 * The Proto Buster in Mega Man: The Power Battle and Mega Man 2: The Power Fighters was brought down to normal strength shots and charge shots like the Mega Buster, and in the latter, Proto Man was able to use Proto Strike, a short ranged blast.
 * In Super Adventure Rockman, Proto Man uses the Proto Buster to save Mega Man from three Sniper Joes.
 * In the SNK vs. Capcom: Card Fighters series, Proto Man uses the Proto Buster to attack enemies.

Trivia

 * Although the Proto Buster appears in Proto Man's left arm in most of his appearances, in a few instances (excluding reverse sprites) such as Rockman Complete Works illustrations, it appears in his right arm.