On the first time i have to say, this is a very clean style, but so much impressive, the colours in this image are dramatic and poetic...
your sources were very well chosen... the sensation of movement is present.
details on the horse are subtle and well thought out. And also the wings are perfectly fitted on horse!
the lighting is moderated, but with the correct intensity for not disturbing the hightones...
At more, the only thing i would change is the signature, the typography you choose is very beautiful, but the position i do not like... but of course, its very beautiful signature!