That actually never crossed my mind...

Well if you look at the Hero's Journey, the mentor never finishes the journey... EVER!

But Twilight's story isn't that of The Heroes' Journey.

Good point.

I guess I just over think things :lol

This is my reaction to Smile HD.
http://www.youtube.com/watch?v=WtOPacnjxLU

Princess Celestia's mission to Twilight when she sent her off to Ponyville to act as supervisor for the Summer Sun Celebration was "Make some friends."
Sunset Shimmer's failing was that she was more interested in being the best, learning as much as possible, so she pushed others away so that she could learn more and become more powerful, thus never learning anything about friendship.
Their similarities are easiest seen when they are both invited by a group of ponies to a party or event, but writes them off so they could study more.
Celestia didn't tell Twilight to make friends so she could wield the Elements of Harmony. She told Twilight to make friends so that she wouldn't become like Sunset Shimmer.

Sunset Shimmer doesn't seem as such a generic villain now, does she?

I love the IDW comics, and I love how they tied Sunset and Twilight together in a manner beyond just "Celestia's students."
It presents a nice duality between the two characters and holds the "We're not as different as you think" theming a lot better than some other series try.

I was going to do that whole "I'm looking at you {insert series name here}" thing but I couldn't think of a good example of a show that tried that and failed. :lol