Why Marvel Didn't Want Paul Bettany to Play Ultron In MCU's What If

Warning - This article contains spoilers for the Season 1 finale of What If...?

The MCU's first animated Disney+ series What If...? has officially wrapped up its first season with a finale that posed plenty of questions.

Throughout its nine-episode run, What If...? showed what would happen if Marvel's most recognizable characters took a different path. From Peggy Carter taking the super-soldier serum to a zombie virus infecting Earth's mightiest heroes, the series culminated in a finale that saw these parallel-universe characters coming together to fight Ultron. 

The question What If...? asked about Ultron was what would happen if the villain had successfully been implanted into the vibranium body he created for himself, which ultimately ended up as the character fans know as Vision in Avengers: Age of Ultron.

Interestingly, the What If...? team chose not to use James Spader, who voiced Ultron in the film, or Paul Bettany, who has played Vision across multiple Marvel projects, to voice this new version of Ultron. Instead the team brought in Red Skull actor Ross Marquand; as it turns out, there was a good reason for this decision.

The Reason For Ultron's New Voice

In an interview with Entertainment Weekly, What If..? head writer A.C. Bradley and director Bryan Andrews discussed the decisions behind the season one finale. 

When asked why Marvel didn't bring Spader or Bettany in for the role of Ultron, Bradley said it would "be too much of a disconnect" to ask the audience to believe this character was Ultron rather than the Vision everyone knows and loves if Bettany had voiced the character. She also spoke highly of Marquand and said that his "chilling performance" helped make it clear that this was indeed Ultron:

First of all, I love Ross Marquand. He's the nicest guy. Last summer he was at my house drinking wine and my cat got out and me, him, and a few friends literally wandered the streets looking for my cat, so Ross Marquand always gets a thumbs up from me. We wanted Ultron to be as terrifying as possible, because he's terrifying, and Paul Bettany is the loveliest man on earth. He is such a sweetheart. We felt that, if Paul Bettany using Vision's voice voiced Ultron, it would be too much of a disconnect, because we're asking the audience to believe that this is Ultron in Vision's body and not Vision. So by having Ross step in and give an incredibly chilling performance helped us make that clear to the audience, especially people who aren't as familiar with Age of Ultron, Vision, and that whole canon as we are

Andrews followed up by saying the move to re-cast Ultron in What If...? "just seemed to make sense." He also pointed out that without the Jarvis A.I. making its way into Ultron, there would be no reason for Bettany's voice to be involved and that this new villain "could probably choose to sound any way he wants":

It just seemed to make sense. Because in Age of Ultron, they get some version of Jarvis A.I. into Vision so it makes sense that it's that A.I. with that voice that comes out of that body. But the body can be whatever voice it wants because it's this amazing thing of tech. So if a pure Ultron A.I. gets in there, there's no reason why it would sound like Jarvis. It's Ultron injecting himself into this shell, so it's his personality. He could probably choose to sound any way he wants. What's interesting is it makes for a brand new type of disconnect where people are seeing Vision's face and they want to hear that voice that they love so much, but they get this evil voice coming out. It's an extra layer of unsettledness and tension.

What If...Ultron Had A New Voice?

With this show coming as the first animated series set in the MCU, a lot of the excitement around What If...? has been focused on which actors from the films will reprise their roles in the series. 

Paul Bettany had already returned to voice Vision in What If...?, so while it may have seemed logical for him to return in this episode, Andrews points make sense. As the director pointed out, Bettany originally entered the MCU as the voice for Tony Stark's AI Jarvis, and it was this integration that made Vision the character he was. Without the Jarvis AI, the body of Vision was just an empty vehicle.

Spader's return may have made more sense here, as he portrayed the villainous Ultron AI. In the end, not every legacy actor has been available for What If...?, so it's likely Spader's return just wasn't possible.

In lieu of this, casting Marquand as What If...?'s Ultron was a decent option. The actor already had experience portraying one Marvel villain and he was already on board for What If...? to play Red Skull. Ultron in episode 8 was essentially an entirely new version of the character, so it makes sense that he would get a new voice as well.