Paul Bettany played it coy at Comic Con yesterday regarding his role as The Vision in "Avengers: Age of Ultron", but did tell Slashfilm that his character "feels paternal to a number of people" and he's "really good at punching".
The robotic character is learning about the world, processing things in the moment at an exponential rate, so he becomes more sassy as the movie continues:
"It’s been a really lovely working experience. In the plot there’s a lot of distrust, and that has to be navigated by the Vision. He does it in a quite extraordinarily shocking way. It’s a real roof raiser of a moment."
He confirms he has a cape, but wouldn't say the color. His costume design is made out of "materials that haven’t existed for a long time" which makes it cool looking but very uncomfortable as it's hot as hell.
The character can also change his density, a fact that Whedon reportedly exploits several times in the film.