I love Luna because she is so conflicted, she was viewed as evil because she wanted so badly for all of the ponies to rejoice in her beautiful night, moon, stars, etc. When we see her return to her true form you can see in her eyes that she is ashamed for what she did and that she is fighting demons in her mind every day and night. But she fights it, and she pushes it away in order to help show ponies that she has changed and that she can be loved. I feel like I can relate a lot with her on this level where she has a lot of fighting to go through to be happy and finally okay with herself. Through her friendships and the love of her sister I know she will become more confident and strong.
Didn't mean to go too deep there! But yeah, she is a pony that is stronger than everypony realizes. And she starts to learn how to accept and forgive herself in order to be stronger.