When I first looked at this picture I was a bit confused, because there were stars in front of the body. After looking a bit closer I realized it is totally normal for Nightmare Moon. xD
It looks really great, especially with that armor and her grin, I just love it! And since I hope to help you improving I'd like to point out that the part of her front leg that is closer to the body looks a bid weird to me. Like there would be an additional joint.
My all in all impression can be described by using the simple word "wow", though. :3