I've already posted this as an entry for the competition, but I thought I'd share it here, I made slight improvement to get it more contrasty and played with the cloudiness and transparency a bit too.
Feel free to provide constructive feedback, but to be honest, I may be ready to move on to my next render because I just had some new render ideas. I just want to share some of the cloudy render here :)
The top one is original, bottom is updated version.