I'm not an expert on photography, so forgive me for some of my naivety if it shows throughout this critique, but I hope I can be of help with what knowledge I do have, and my initial thoughts when seeing this photograph.
First of all, it's shot at a great angle, very disorientating and really captures the fact that they're fighting (I assume!) very effectively. The costumes look great, and the models fit them really well too. Great makeup. Zafina looks good, has a good facial expression but perhaps could do with a slight hint of pain, because it doesn't look pleasant how she's being attacked by Nina!
The location is great too, quite simple and neat and doesn't draw attention away from the main focus: the two girls. And your photographer is of course wonderful for blurring the background and focusing the foreground fighters. Really gives it that extra boost.
The main thing that really irks me is the fact that Nina should be pulling Zafina's arm much tighter, to the point where it's completely straight, because if she's really fighting and that's her move, that'll really hurt about as much as hitting her with a pillow! (unless the pillow's filled with bricks...XD) So definitely needs to look more realistic in that sense - really make it look like they're hurting each other! That goes for Nina's facial expression too, Nina has quite a stern face, very fierce and angry most of the time, and I don't feel the model quite captured that - she needs more anger and ferocity!
Overall it's a really, REALLY great photo and you just don't see this often at all, especially to this quality and originality. But I have conveyed the issues I have, which I certainly wouldn't say ruin it, but definitely somewhat deteriorates the overall impact. I hope this has been useful! ;D