This is a great sketch! It's always nice when you tell how long it took you to make something so epic. I think her breasts are a bit out of proportion, though. The colors are just plain wonderful. The background is what really spells it out. You see the best use of colors there.
Is this an original character? You just made it sound like it was something you came up with. I wish we could see more of the wings. I just now noticed the spiked crown. This is just great to look at.