Sweet Celestia this is incredible. I am in awe.
Vision: 5/5! Not only is this concept intriguing, it's also realistic. I can totally see Chrysalis capable of this.
Originality: 5/5! I don't think I've ever seen anything at all like this. This is that one single idea I wish I'd had. Seeing Twilight like this makes me want to see other changeling-ified ponies...
Technique: 5/5! I stared at this piece for 3 full minutes looking for a fault or mistake, and yielded no results. It's incredibly show accurate, and an eye for detail as well. I love how the greens on their backs blend together.
Impact: Once again, 5/5! Twilight's expression almost made me cry, and Chrysalis is obviously happy to have an Element of Harmony in her twisted possession. This may be just me, as I am a sucker for transformations and emotional moments.
Overall: 5/5, and it deserves no less. Everything about it is wonderful and interesting. My only question is, who's next?