Ironman 3 (Extremis)

Part of Tony's new personal dilemma is him fighting other whether the suit defines him or does he define the suit.

He's said that he and Iron man are one, but which one is the dominant part? Obviouslhy the answer is they're two parts of the same whole. And the whole is greater than either sum of its parts and all that.

...or it could be a ploy from The Mandarin to sabotage the newest iteration of the armor via nanotech.