This work is amazing, and all your gallery is amazing!
And i don't know why you say that the composition on this work sucks... Maybe the first that catch you eye, are the people on the left, but, as soon as I've seen them I know that they are going to die... xD
The level of detail in this piece is simply amazing! And while the background does feel a bit washed out with the overly abundant rain effects, it works well for the piece as it places a large focus on the character in front.
I'm not entirely sure on how to suggest better rain and moister effects, but there are bound to be several tutorials on the net that cover that particular area. Also, are you using Photoshop? If you are, there's a plugin or filter you can use to help with creating wet or moist effects in several version of the program.