This is a cool image, but looks a bit choppy in your mixing of the two styles.
I really like the background of this image. The stars and the Aurora Borealis,(Or Aurora Australis) are very nice looking and interesting. I like how many of the lines of the sky point towards Zubat, giving the effect of leading lines. I think Zubat looks a little too pasted onto this background
I really like the colours of the sky and the Auroras in the sky, but I just wish that the colours matched with Zubat, as it seems a bit disjointed colour wise, but that may have more to do with the shading of it. The light source/direction of light on Zubat is completely different from what the background makes it look. If it were matching, the light would come from above, rather than what it looks like the light is coming from the right/bottom-right on Zubat.
Zubat looks fairly like it should, except for the wings are a little messed up sizing wise. I'm sure you can see that without me really criticizing you for it.
I think, although you have made it a little dis-jointed looking, it is passable. You get a 40, and a new friend, enjoy!