I kept messing with this drawing and no matter what I did I just wasn't satisfied with it. After struggling with it for a couple of days I increased the size of the ax to super ridiculous proportions and then it finally worked (well, for me anyway).
Drawn in Photoshop on the graphic tablet.
Here's the original sketch (yes, it was drawn on lined paper). This one changed quite a bit in the final drawing; he gained an open war-cry mouth, a more dynamic pose, and the aforementioned ridiculously large axe.