I like what you've done here. I really love how the background turned out :D
The transition of the magic kind of thing and the ground could be smoother. I feel like this part of the wallpaper could use a bit more work. I think you should add similar 'magic swirly' brushes nearer to his feet, or maybe, if you can, have fissures of ice. There should be more brushing in front of the character's foot.
There is also the sudden colour change on the ground. I would be nice if that was less noticeable.
Overall, good job :)
