Target Acquired, PROTON CANNON!!Iron Man
Proton Cannon is a Hyper Combo that appeared in every game in the series since Marvel vs. Capcom: Clash of Super Heroes. It was one of War Machine's Hyper Combos in Marvel vs. Capcom: Clash of Super Heroes and Marvel vs. Capcom 2: New Age of Heroes. Iron Man gained Proton Cannon and has used it since Marvel vs. Capcom 2: New Age of Heroes.
Iron Man summons a gigantic repulsor cannon and mounts it on his shoulder. He then proceeds to fire off an enormous beam directly in front of him. War Machine's version is the same, but when he goes "Golden War Machine Mode", he fires a barrage of missiles instead.
Proton Cannon has a slow start up time and can easily be interrupted by a fast attack thus ending the Hyper Combo, so using this move haphazardly isn't ideal. Although if the opponent is directly in front of Iron Man while activating the hyper combo causes them to get hit by the cannon when its summoned. However, opponents can get behind the fired beam and punish Iron Man.
Angled Proton Cannon
Angled Proton Cannon (対空プロトンキャノン, Taikū Puroton Kyanon?, lit. Anti-air Proton Cannon) is a variation of Proton Cannon in Marvel vs. Capcom 3: Fate of Two Worlds, Ultimate Marvel vs. Capcom 3, and Marvel vs. Capcom: Infinite.
It is virtually the same, the only difference is Iron Man can angle it to aim up at a 45°, making it a good anti-air attack.
- “Target Acquired, PROTON CANNON!!”
— Iron Man
- “Here's my Sunday best! PROTON CANNON!!”
— War Machine
- “Here's the big one... PROTON CANNON!!”
— Iron Man, using Angled Proton Cannon
- Marvel Database: