This is a great image, it makes luna look like a nicer and less scary character. I think that the way you lightened the area around luna, this makes her seem nice and caring. I also like how the mountains and canter lot are used. This image is dark and interesting and overall it is very good.
Now I will talk about the negative aspect to this image. I believe that the bottom of the image is boring and should either have something in there or it should be cropped out.