Battle mode initiated! What part of 'Invincible Iron Man' did you not understand? So, you doin' anything after this?
--Iron Man
Iron Man's first appearance was battling Morrigan while both were airborne. Later, with the appearance of Galactus and dangerous villains determined to conquer both the Marvel and Capcom worlds, Iron Man ceased battling Morrigan and turned his attention to stopping the villains. He is later seen saving Viewtiful Joe from plummeting to his death after Joe and Amaterasu unsuccessfully attacked Super Skrull, flying alongside Morrigan (who saved Amaterasu) towards the New York mainland. Iron Man then helps to rally together more Marvel and Capcom heroes, who take the fight to the enemy.
Iron Man's MvC3 ending involves him noting in his journal that uploaded battle data, gathered from his climactic battle with Galactus, shows that he was barely able to defeat him. To better prepare himself for any future threats, Iron Man uses the battle data to build the new Galactus-buster armor.
When Iron Man is facing a female opponent, except for Amaterasu, he will quip "So, you doin' anything after this?", a reference to his infamous playboy status in the comics. A somewhat disturbing oddity in this quote is that he will even flirt with Tron Bonne, who is only 14 years old, making Iron Man look like an ephebophile (an adult who shows sexual preference for underage partners who are generally between the ages of 14-16).
Iron Mans ending in Marvel vs Capcom 3 has him analyzing data and technology gained from his fight with Galactus and creating a new Iron Man suit.
In Mike Haggar's ending in Marvel vs. Capcom 3: Fate of Two Worlds, Tony Stark serves as Vice-president of the United States along with Haggar who takes the role of President.