What really strikes me about this image is the face. Nyx is a statue. There isn't a part of her that looks particularly real or forgiving. The female curves serve only more as a reminder of something she probably used to be. Its her face that really draws it in, the most human aspect of her; and it seals the deal of her inhuman fate. Your color palette was very well chosen for this. The watercolor idea for the background and the name adds to the artificial sense of her nature. The "brightest" part of her is her hair, but rather than standing out, it seems more corpselike due to its presence. I think you did a wonderful job.
If this were the cannon, I would not only have no problem with it, I don't think I could be happier. I love the way you portray their colors. Human in appearance, alien in presence... truly frightening.