Well, for starters, I would stay focus on the shading for the sword. I would suggest to re-do your color palette and use better value. Your primary color is fine, but the shading to it isn't. It's too light towards the dark and it makes the shading too vague. I would say that you need to extend the palette with 2-3 colors on the shading, and 2 colors on your highlights.
Fix the thickness of the sword, too, it's uneven.