I know you asked about the design but my feedback is going to be about form, and you'll see how important it is and how it affects the design in the end. Basically, you're too focused on trying to add shapes and details, but you're not paying attention on how your elements all fit in space, most elements feel like a flat shape stuck on top of a silhouette, like you only think in screenspace, or 2D. You have to think in 3D, in order for each element to wrap around the form, the ellipses should wrap around most things cylindrical, the center line of his torso should be slightly to the side because it's seen in 3/4 view. The knee pads should describe a C curve because it wraps around the knee, every element should be thought out as a 3D object. In my paintover, i barely changed anything about your design, if it looks better, it's only thanks to the fact it's now treated as form and not just shape. So my suggestion is : work on your mannequin and simplification of the human body, and learn how to draw basic forms in space, how a cylinder looks from this or that angle, it will help design so much. And after that, i also suggest looking up armor and clothing references, but that's secondary in my opinion. Hope this helps | Artwod Feedback