If you keep it up I think you will learn alot from working with this piece. There is good improvement so far.
There are a few anathomical errors that you might want to address. He doesn't have a neck for example, but most people don not have their heads attached directly to their shoulders. He also doesn't have knees (might be easier to edit this with shading). I'd suggest that you make his tunic a bit shorter and the legs slightly longer so that the knees are visible. The boots also look very narrow around the shins, so you might want to make them a bit fatter there, to show that his trousers (tights) are actually tucked into them. There is a very huge difference between his shoulders and then very slim over-arms, maybe make them a pixel or two wider? I would also suggest that you work some more on the face, making it slightly smaller, giving him a bit more realistic eyes (with whites in the eyes), a nose, and also either some hair at the sides of his face or ears. You have done a great job with the detail on the shield, but to weigh up the piece you need to add more details overall. First off - to make the clothing look less flat, you can study folds and try to apply them to the clothes. Just google "skirts", "shirts" or "tunic" and I'm sure you'll find some photo reference.