<P> By April 2013, filming was scheduled to begin in early 2014 at Shepperton Studios in England . At the Hollywood premiere of Iron Man 3, Whedon said that he had completed a draft of the script, started the storyboard process, and met with actors . Whedon also mentioned that he wrote with Downey in mind and included a "brother / sister act" from the comic books, later confirming that he was referring to Quicksilver and Scarlet Witch . Whedon explained his rationale for including the characters in the film saying, "their powers are very visually interesting . One of the problems I had on the first one was everybody basically had punchy powers...(Quicksilver)'s got super speed . (Scarlet Witch) can weave spells and a little telekinesis, get inside your head . There's good stuff that they can do that will help sort of keep it fresh," though cautioned he was not throwing in more characters for the sake of doing that . Whedon stated that the twins allowed him to add more conflict: "They don't like America, and they don't like the Avengers...The Avengers are like a world power, and not everybody's on board with the Avengers coming in and starting fights, even in the name of justice . So you need that dissenting voice, and you need to understand it and sympathize with it ." Because Marvel Studios shares the film rights to Quicksilver and Scarlet Witch with 20th Century Fox and had to avoid conflict with Fox's X-Men films, Whedon introduced two important characters into the Marvel Cinematic Universe completely on his terms for the first time, which allowed him to connect their origin stories to the universe that they created and avoid the concept of mutants . Whedon relished at the storytelling opportunities by introducing a character with telepathic powers, explaining, "it meant we could spend a little time inside the Avengers' heads--either their past or their impressions of what's going on, or their fears, or all of the above ." By May, Downey had entered negotiations to extend his contract with Marvel Studios and reprise his role as Iron Man in the film . A month later, Downey signed on to return for the then - untitled Avengers sequel, as well as a third Avengers film . </P> <P> At the 2013 San Diego Comic - Con International, Whedon announced the film would be subtitled Age of Ultron . Despite the subtitle, the film is not based on the 2013 comic book miniseries Age of Ultron . Feige explained that they simply liked the title Age of Ultron but the plot was taken from decades of Avengers story arcs . Whedon added that Ultron's origin would differ from his comics roots, and that Hank Pym would not be involved with Ultron's creation . Whedon disclosed that Edgar Wright had rights to the character first through his inclusion in Ant - Man, which was already in development . He also thought that Ultron needed to be conceived through the Avengers and since they already had Tony Stark and Bruce Banner on the team, it would not make sense to bring in a third scientist . Whedon also said the film would have a darker tone due to Ultron's involvement . </P> <P> The title of the film came as a surprise to many fans who were expecting Thanos, the mastermind behind the events of the first film, to be the main villain in the sequel, with Whedon saying, "Thanos was never meant to be the next villain . He's always been the overlord of villainy and darkness ." Commenting on finding the right balance between technology - and fantasy - based heroes in Avengers: Age of Ultron, Feige said "Iron Man is a very technological hero; his movies are always technologically based . The first Thor was all about introducing Asgard and Thor in that more fantastical realm into the more reality - based MCU...As we go into Ultron clearly he does come out of technology, but we're using all of our tools at our disposal that we've established so far as part of the MCU to build the storyline of Age of Ultron ." </P> <P> Casting continued into August 2013, with the announcement that James Spader would play Ultron . In November, Marvel confirmed that Elizabeth Olsen and Aaron Taylor - Johnson would play the Scarlet Witch and Quicksilver, respectively . Taylor - Johnson had been in negotiations since as early as June, while Olsen's potential involvement was first reported in August . By the end of the year, Mark Ruffalo, Chris Evans, Samuel L. Jackson, Chris Hemsworth, Scarlett Johansson, Jeremy Renner and Cobie Smulders were confirmed to be returning to their roles from the first film, and Don Cheadle, who portrayed James Rhodes in the Iron Man films, had committed to a part in the film . In the early months of 2014, Thomas Kretschmann was cast as Baron Wolfgang von Strucker, Claudia Kim was cast in an unspecified role, and Paul Bettany, who voiced J.A.R.V.I.S. in previous MCU films, was cast as the Vision . Whedon said "juggling" all the characters in the film was "a nightmare" explaining, "They're very disparate characters . The joy of the Avengers is they really don't belong in the same room . It's not like the X-Men, who are all tortured by the same thing and have similar costumes . These guys are just all over the place . And so it's tough . Honestly, this is as tough as anything I've ever done ." </P>

When does avengers age of ultron come on tv