It's just a speedpaint for that daily art challenge. It's a wizard duel of some sort. Makes me want to play some M:tG.
The theme is perspective.
I tried to give it a sort of atmospheric fog, but I think I got carried away. It didn't help that the board ate some of the smaller details when I uploaded the picture.
Reversing green and blue for the land and sky was rather interesting, and I did have fun with the perspective.
The time taken was just under three hours.
You can see how it was drawn here: [link]