Overall

Vision Vision

Originality Originality

Technique Technique

Impact Impact

Rainbow Dash's expression and posing on this stark background is really hamming in on emotion. I could definitely see Rainbow in an animation like this, flying through with that classic rainbow streak behind her and completely demolishing whatever is attacking the town or even Equestria (I think that's how you spell it).The only thing I think is off about it is your shading. With the way your clouds look, it should either be morning or evening, when the sun is about to rise or set. So she should either be backlighted or even silhouetted, or the light should be coming from her left, which would make shading minimal because of your light source coming from where the audience should be sitting.With that in mind, the shading you have currently, the eyes should not be in light, or maybe the eyebrows and the very tip of her muzzle should be the only thing on her face that it lit up. But the way her armor shines in that sunlight is wonderful, and the wings are shaded absolutely perfectly.