On the relationship of Michael Fassbender’s Magneto and James McAvoy’s Professor Xavier at the end of Days of Future Past, Kinberg said the two still are friends but Magneto will always be Magneto in the end.
Two New Websites Offer Hints At What ‘X-Men: Apocalypse’ Will Be About
"At the end of the movie [Magneto] flies away without his helmet, with the implication that he’ll go off and continue to be Magneto in some form, but not be able to hide it from Charles, who’ll be able to read his mind and track him," Kinberg said.
“There’s a truce of some kind between Charles and Magneto, but there’s a part of Magneto that will always be the Magneto we know from the comics.”
http://www.enstarz.com/articles/47235/20140927/x-men-apocalypse-movie-news-simon-kinberg-talks-michael-fassbender-james-mcavoys-relationship-hugh-jackmans-claws-nightcrawler-video.htm (via mc-meow-avoy-fassbender)