Tony Stark has been going through changes in the Marvel Cinematic Universe. The arrogant, aloof billionaire we first met in IRON MAN has evolved not only into a superhero, but one with a shifting philosophy. Gone are the days of laughing off Senate hearings and casually hacking S.H.I.E.L.D. secrets while aboard the Helicarrier. Tony is now in the opposite position of craving authority, whether it’s looking for an artificial intelligence solution in AVENGERS: AGE OF ULTRON or advocating government oversight for superheroes in next year’s CAPTAIN AMERICA: CIVIL WAR. It seems like Tony has lost much of that surplus of confidence he’s carried around his whole life, but really, it goes much deeper than that.

In a Q&A session for this Friday’s Blu-ray release of AVENGERS: AGE OF ULTRON, I asked Marvel Studios President Kevin Feige and Senior Vice President of Production Development Jeremy Latcham about the dramatic shift in Tony’s mindset. Feige explained, “It really is in large part the events of [AVENGERS: AGE OF ULTRON]. Even Tony can be self-aware enough to go ‘Maybe if I shared my plans with somebody, this might not have happened.’ I think we are seeing a Tony that is trying to become more responsible and there are things that happened between the movies that we learn about in CIVIL WAR that make that even more personal.”

Latcham, also an executive producer on AGE OF ULTRON, expanded on the idea of responsibility, pointing out that it’s been part of Tony’s journey from the beginning. “I think responsibility is kind of the main theme for Tony as he’s kind of evolving as a character. Originally he’s a guy who had been part of some pretty terrible things and says, ‘I’m gonna do everything myself and that’s the way I can know it’s right.’ And he starts to run with that and then you see what happens and maybe you need balance. I think that’s a really fun thing to watch a character kind of grow up over the course of all these movies. Where’s the line? I think it’s gonna be fun to see in the next one.”

Responsibility is what drove Tony out of apathy and into an iron suit in the first place. After seeing firsthand where much of his fortune came from, Stark weapons in the hands of terrorists, Tony was compelled to act and did. He saved the day a few times, which reinforced the idea that he was the best man and best mind for the job, so it seemed like there was no need to rely on the input of others. A small but significant change occurred when he started believing in Captain America, a.k.a. Steve Rogers, in 2012’s THE AVENGERS, but as we saw in AGE OF ULTRON, Tony still saw saving the world as ultimately his job and one he could not do without inventing something even better than himself.

Though Tony did not technically create Ultron, he certainly provided the opportunity for Ultron’s existence. Tony was able to balance the scales by also creating Vision, but we are definitely going to see the next major step in the evolution of Tony Stark on May 6, 2016. Responsibility must now be accompanied by accountability, placing Tony in favor of government control of The Avengers and anyone else wanting to be a superhero.

Tony is not becoming the bad guy in CAPTAIN AMERICA: CIVIL WAR. He’s actually trying to prevent that outcome by giving the world some say in the actions of men, women, and gods with unimaginable power. That’s not an evil point of view, but one that is perfectly reasonable.

Ordinarily, Steve Rogers would be inclined to agree with Tony on this issue, but specific circumstances have Steve taking the opposing side. Just as Tony has slowly learned to put his trust in others, Steve has learned that there is no one he can trust. Feige explained, “Captain America’s come to a point having encountered Hydra, having encountered the World Security Council where he says ‘We can’t listen listen to anybody else. That’s how corruption begins,’ and [Tony and Cap] don’t get along.

It’s fascinating to think about how Tony and Steve have practically flipped sides and philosophies from their first films to CAPTAIN AMERICA: CIVIL WAR. What’s even more amazing is how their respective arcs have been so well constructed that each character’s evolution feels completely genuine. It’s going make their conflict next May much more meaningful while avoiding the over-simplified trap of making one character clearly wrong or out to be the bad guy.

Where the line is and which side of it one is on are going to be very interesting questions for both the characters and the audience to explore.