Magneto even changes accent during X-Men: First Class when at the end on the beach scene Michael Fassbender is suddenly using his natural Irish accent. Maybe it was being used to show the character had transitioned to the evil side...Well, seeing how the X-Men movies were all "Don't give a damn" with accents by having Xavier and Magneto speak with British Accents when neither are (Xavier is American and Magneto is Polish) I'm glad MCU stayed true here.