According to Comic Book Movie on Monday, Simon Kinberg spoke in an interview in regards to the ending of Bryan Singer's "X-Men: Days of Future Past", the final good-bye's to the original characters, and the ability of the Marvel Cinematic Universe's challenge in handling two different Quicksilver characters. Kinberg mentioned that he wanted a feeling of resolution at the end of the film for both Professor Charles Xavier and Magneto. The screenwriter also emphasized that with the original X-Men, he desired a focus on each of them a degree of finality.
There also existed a character role reversal between Logan and Professor X. The irony of the situation entailed Logan's knowledge of the professor in the future as well as the issue of figuring out how to get Professor Xavier to that point from the past. Also the bringing together of the two Charles was an emotional time on set as both Stewart and James McAvoy meet face-to-face.
Kinberg felt that the original five or six characters "had beginnings, middles and ends - challenges, crises, breakthroughs." Most of the "X-Men" movies were more Wolverine-focused. Played by Hugh Jackman, Logan was considered the protagonist of the other films, but this time the focus of the main character/hero was upon Professor X, played by Patrick Stewart.
Quicksilver at one time was met with much criticism initially, but fans seemed to have been impressed with him after all. Kinberg was approached about how the Marvel Cinematic Universe would be able to handle him in the "X-Men" sequel and "Avengers: Age of Ultron". He also made note that the four actors from the "X-Men" franchise all had experience with "Macbeth" and how it would be comparable to the movie. Kinberg also said in the original draft it was a young Juggernaut that was meant to break Magneto out of the Pentagon.
"I'm sure they'll do a good job with it. Macbeth is an interesting one because all four of our main actors -- McAvoy, [Michael] Fassbender, Ian, Patrick -- have done famous productions of Macbeth. If the world can handle that, it can definitely handle two Quicksilvers."
Singer's "X-Men: Days of Future Past" is open currently in theaters.