No offense to Prof X/McAvoy lovers, but THE X-Man is Magneto! If this is going to be a cover story for an upcoming Entertainment Weekly, they better send me the Magneto cover. That's all I'm going to say!
I've been reading some nerdy informative X-Men fanboy pages to determine what is the consensus of which X-Men is the most powerful and feared. Although there is no unanimous decision, frequently Magneto was in the top five. As was demonstrated in that Comic Con interview with the Professor X and Magneto actors, Michael and Ian immediately and in unison, came to the defense of their character:
Interviewer: And then there is the villain... McKellen and Fassbender: No. Interviewer: Misunderstood freedom fighter? McKellen and Fassbender: Yes.