Bout time I write one of these for your art. Time to critique I guess.
VISION: There are parts of this that feel pretty ambitious. In particular, her armor, as well all the chains. However, I'll be honest and say the lack of major detailing on her mane is noticeable, but doesn't come to close to ruining of course. Very well done on the whole.
ORIGINALITY: I have seen ponies in Chaos armor floating around, but I haven't really seen any of Fluttershy paired with Khorne (what an odd mix, rofl). This takes an existing idea an puts a new spin on it, and I very much like that. Very awesome.
TECHNIQUE: Your technique on this is very good. There doesn't seem to be any stray lines, the shading is good, and the outlines are nice and crisp for the most part (if there are any lines that aren't, they don't immediately pop out. Very nice.
IMPACT: I think this leaves a pretty good impact for those that view it (especially for Bronies familiar with WH40K and the lore for Chaos). I can't get the image of Fluttershy gliding around slaughtering hundreds with Lightning Claws out of my head, for some reason.
Overall, very well done! Can't wait to see what other Chaos mash ups you have planned in the future!