Yup, NBA Jam rocks lol.
Anyhow, the biggest problem I think is the fact that he appears to be looking at the ground rather than straight ahead. Even if he is hunched, he should look like he's walking with some purpose (unless he's a zombie dog-wolf of course, but I doubt he'd have the coordination to use swords lol). If you angled his chin a bit upward more, you could both turn the head a lot more easily as he walks (by shifting pixels a little left and right) as well as give him a bit more fearsomeness since he looks like he'll look more like he's coming for you.
I think the only other issue is that his neck may be too long -- it kind of looks like a man wearing a dog-mask rather than that being his actual head.
Finally, for the sword swinging animations, give the guy a little arc in his motions -- as I mentioned before. Lean him in and make his arms and legs swing the sword together while following the arcs that you think will make the attack look more powerful.
Also, add some blur on the blade between such a long swing of the blade in such a short amount of time. This blur will help you visualize the arcs better too, and, in addition to that, it will pull the frames closer together, making the swing read more clearly on such a small amount of frames.
Hopefully that helps clarify some of your issues.