10 Superhero Movie Staples That Weren't In The Comics
6. Tony Stark Creates Ultron - Avengers: Age Of Ultron
Though Avengers: Age of Ultron might feel like a world away these days, Tony Stark's creation of Ultron (James Spader) is unquestionably one of the MCU's most pivotal events so far.
Ultron was designed as a fail-safe following the events of the first Avengers movie, but after Ultron nearly annihilated the world, Tony was left severely affected, and it served as the catalyst for him signing the Sokovia Accords.
Despite presenting as such a major character through-line for Tony Stark, this was actually changed from the comics, where Hank Pym is in fact Ultron's creator. In both cases Ultron serves as a mirror-image of its maker, yet the overall implication is quite different.
You can certainly argue that this change robs Hank Pym of a major character arc, but given that Pym wasn't an MCU fixture at the time of the film's release, it certainly made sense to re-work it for the benefit of Stark's character development instead.