Empire also spoke to Whedon and producer Kevin Feige about what fans can expect form the big Avengers sequel.
"It's more epic and in other ways it's more noirish and suspect and devious and specific," said Whedon.
"Ultron, he's got a touch of the apocalypse in him." Adds Feige, "Ultron was the villain Joss wanted, from midway through production on the first film, to have serious repercussions for The Avengers."
Whedon and Feige also spoke a bit about the Iron Man's Hulkbuster armor.
"It's a bespoke suit," says Feige, "the back-up plan in case things go awry."
"The Hulkbuster is from after my time [as a reader]," says Whedon, "but even I knew what a big deal it was. It makes sense because there's no one who can really go up against Hulk, but more importantly, those guys are best friends, so what that battle is and what it means is fascinating to me."
Avengers: Age of Ultron opens May 1, 2015.0comments