Oh my my my I love it!! I'm probably really insufficient for writing a critique but I will say that I certainly love the costume, the setting is nice considering you were at convention (I think ideally I'd rather see something more mountainous/rocky with a dragon-slaying warrior chick) annnd again, you were working with mostly natural light, but more interesting lighting could definitely bring this photo to life
This is my perspective as a model, not an artist so don't think I consider myself an expert or anything.
The model is beautiful, the outfit is cool, the background looks very good except for that big window (is that a window??) by the way, the sword and the dragon head are cool to. only one thing i didn't liked, the armband is too tight and gives a bad look to her arm.
pd: great work (I hope I have been helpful) pd2:Google translator sucks asdfffctrl pd3: I just looked at the picture again, damn, she is really hot dude!!