Vision: I like the idea that you went for here, as their are far too many pictures of the mane six as the Elements of Harmony. It's refreshig to see that someone remembers when they were the exact opposite of that.
Originality: I like the main effect that you were aiming for, but I honestly think that you could have handled the actual execution a bit better. It just seems too simplistic, and there really isn't anything that pops out to the viewer. I did like the mainly monochrome art style, but the picture is just crying out for more in it, a certain je ne sais quas if you know what I mean.
Technique: The technique is fine, and I really did like the smoke effects in here, as it helps to give a more ominous, ethereal quality. My only real critique here is that you gave them all the same eye shape. It probably would've scored higher if you had mixed it up a little, maybe used some of the eye designs from those episodes.
Impact: Again, this really didn't stick out much to me mainly because of how little there is actually going on in the drawing itself. Some more movement, maybe Discord in the background, even a redesign of the actual Elemnts themselves hovering overhead, that would've carried some weight to it.
Overall: A good drawing, but just too little going on for the viewer to dwell on it much after it's been seen. I'm not saying that it's bad, but variety is the spice of life, and status quo is the starch, and you want as much spice as you can get away with. Keep up the good work, and I hope to see something really good come from you later down the line.
I forgot to add that Chrysalis turns everyone in ponyville including Twilight Sparkle into her mind controlled slaves, like how Baby turned everyone into slaves in Dragonball GT, except she doesn't multiply. Sorry about that. Again Good artwork Jamey.