Good pose and anatomy. It gives him a feeling of power and strength due to how grounded he looks, though having him leaning forward a bit more would give the impression of him putting more force into the stab.

I like the icy blue tones that you used, though I think adding a few more touches of the gold, green, and red accents you used, especially in the bottom left hand corner, would help strengthen the color scheme. I wouldn't overdo it because I think the drawing benefits from being mostly blues, but a few bits of the other colors mixed into the shadows would help make it more balanced. The steam/wind effects you added are a nice touch, also. They move across the drawing well, adding to an already strong composition.

My only other suggestion would be to sharpen up your edges. Right now it looks blurry, which I think takes away from it.