3. The film twists the origins of Ultron

According to the comic book, Dr. Hank Pym is the creator of Ultron. However, in the movie, Ultron is pulled off as a creation of Tony Stark: a dormant project that goes south, turning against the team.

4. Avengers 2 sees the debut of the Vision

Vision is one of the most controversial characters to be featured in Avengers: Age of Ultron. While details are not known yet, speculations have it the Vision is an upgrade of J.A.R.V.I.S. fathered by none other than Ultron himself. When asked about it, Paul Bettany aired nothing out.