With Vision, Quicksilver and Scarlet Witch all being introduced to Earth’s finest superhero team in Marvel Studios’ upcoming movie The Avengers: Age of Ultron, writer and director Joss Whedon has quite a challenge on his hands when it comes to careful management of all the characters’ screen time and story arcs. Everyone wants their favorite comic book character to join the Avengers, but too many new additions could end up weighing down the Quinjet.