Readability's rough on the last one. Is that supposed to be a sword with fire around it, or a bizarre shield...?
You probably don't need to be told any of the obvious stuff. If I looked long enough I could probably find something for you to rework, but three first three sprites are game ready, in my opinion.
Although if the armor, axe and helmet go together, you'll want to adjust the armor's palette so the shadows better match the helmet and axe.
Critique aside, good work. I like them.
