Vision: The overarching theme of this piece is it's strongest aspect. The unicorn skull and shadow set this piece in a grimdark setting. The solar emblem on her chest indicates she still is loyal to celestia, and she has clearly become some sort of military commander visible through the shadowy soldiers behind her. The fading of her usually vibrant colors indicate that leading them has worn away her previous innocence leaving a cynical worldview and a cocky smile. The shadowy soldiers, and fire set rainbow up as a military commander gone evil willing to burn all in her path. i could go on, but clearly the work has great vision, and a lot of thought has gone into this.
Originality: Unfortunately although the vision was rather unique you did fall upon some rather tired and used art themes. Putting skulls on armor and using shadowy soldier with glowing eyes to make a piece more intimidating is hardy unique. And having your anti hero smile as they watch something burn is probably even more overused. Not that these things are bad, it's just that your work would be able to carry even more weight if you found your own way of depicting artistic meanings rather than relying on already overused methods. Without a doubt the weakest part of your art is it's originality.
Technique:I love almost every technical aspect of this piece. The sparks are done expertly, the little glow you gave them makes them stand out and look more realistic. The shouldergaurd looks great even if the shadowing is a little weird. The feathering on the neck looks great and really draws attention to the face. The warm background really makes RD's stark whiteness really pop. The smirky smile really conveys RD's cockiness perfectly. However, the undoubtedly best part of this piece is rainbow dash's hair. The muting of her usually vibrant hair makes this piece stand out against all other rainbow dash pieces, but more importantly you take advantage of these now muted tones to make her eyes really stand out. It is really great to see her eyes given justice since her hair normally outshines them. My one qualm about this piece is the scantily clad armor, for two reasons. first of all there is no real reason for scanty armor: a full suit would increase intimidation and add to the overall feel better. And second the white belly just draws attention away from the face, which should be the focus of the picture.
Impact: Devastating. this piece truly carries the calm, cocky intimidation of the character in it perfectly. The muted shades make this stand out from both black and white pieces, or color pieces. The eyes are sharp as knives, and they cut to the quick. It truly caries an air to it that lets it stand above the rest. It is beyond worthy of EQD.