THE CHARACTER ARC OF DR. STRANGE

Evil as presented in the movie is strong and mesmerizing early on - but isn't that the case with most things that tempt us? By the end, that same evil has lost its luster. The really cool people in this movie are the ones who are not only fighting for good but who are good. It's nice to have a movie that shows the rise in Dr. Strange's virtue as desirable and compelling.
THE IMPORTANCE OF CHOOSING THE GOOD
Some are arguing that Dr. Strange is actually a villain because he taps into the evil side of this power to bring about good. I didn't see that happening. Strange’s mentor, the Ancient One, is shown to be wrong for making the kind of moral compromise ‘for the greater good’ that actually draws the evil to this universe. Dr. Strange rejects this (though he does later describe her as ‘complicated’, which may be setting up a scenario in which he is drawn to the same flawed justification).
Mordo flatly rejects the Ancient One because he believes all the power into which they tap is evil. That does not appear to be true, but his opinion makes sense considering his experience. We see his start on a path to villainy: he is willing to kill anyone who has that kind of power - once again, for the sake of the greater good. Sound familiar? In the process of fighting the kind of moral compromise he saw in the Ancient One, he has given in to the same siren song of "the end justifies the means." His concern is legitimate; his methods are not. He has the potential of becoming perhaps the most sympathetic of the Marvel villains, one whose means we cannot justify but whose ends may well be more important than we realize.