Now it seems certain that duo would be Quicksilver and the Scarlet Witch, the latter role rumored to be on the verge of being offered to Elizabeth Olsen.
The introduction to the Scarlet Witch to Ultron's story means she might play a significant role in Whedon's rewriting of his origin story.
"I knew right away what I wanted to do with him,” Whedon said. “He’s always trying to destroy the Avengers, goddamn it, he’s got a bee in his bonnet. He’s not a happy guy, which means he’s an interesting guy. He’s got pain."
"And the way that manifests is not going to be standard robot stuff," he said. "So we’ll take away some of those powers because at some point everybody becomes magic, and I already have someone who’s a witch.”
Whedon previously said the film would be doing "our own version of the origin story for Ultron," instead of the standard story in which he was created by the future Ant-Man, Hank Pym.
And while Ant-Man will be getting his own movie at the end of 2015, he may not appear in "Age of Ultron" at all.