The Avengers: Earth's Mightiest Heroes Season 1 Episode 2 : Breakout (Part 2)
A flashback to 10 years before reveals Graviton's origin. In the present, Iron Man is outnumbered by old enemies at the Vault. To escape and fight Graviton, Tony self-destructs the Vault, but his armor was damaged and he radios a replacement from his Chicago tower. Thor, Hank Pym, and Wasp try to fight Graviton. Later, they are joined by Hulk and Iron Man and with their combined power they defeat Graviton and form the Avengers in order to catch the 74 escaped supervillians that escaped the four prisons.