This is by far one of your best pieces in my opinion. I see definite positives like how the direction of the light coming of the sources are correctly placed, and anatomy is also well done. I can definitely tell you spent a lot of time on this, seeing all of the details you put into the fire and hair. The way you made apparent motion in this piece by making the glow move in the opposite direction of the characters, this really helps bring a sense of a dynamic capture.

Now on to some things that could be improved.
There isn't that much as far as I can tell, but one thing that jumped out at me is simply that the glow coming off the eyes could be softened a bit more. Right now it seems a bit harsh. And just paying attention to basic anatomy rules (which you already are quite good at) as in thicker belly area because of the ribcage and strong wing shoulder muscles where the wing joins the rest of the body.

Other than those few things, this is an awesome work of art. It's a excellent example of movement in composition as well as shading technique. Very nice vision that was executed properly, and I've not seen something like this on dA before, so originality gets high points. As for impact, choosing to depict the moment before a collision of two characters is a great way to grab someones attention, so high points there as well.
SO to prevent this critique from dragging on forever, GREAT WORK DANCING DRAGONESS! hope that this critique proves helpful :3