quick edit with contrast/palette adjustments

Sorry for the delayed answer, but curly's edit covers all I was trying to say. Because of the light source is in front of the character, the hood wouldn't actually get any highlighted areas if the shape remained the same, so to emphasize brighter parts on the hood it would be necessary to enlarge the rim around the darkened face to be wide enough to show brighter clusters on the frontal area, which is exactly what curly did.

Your previous attempt also have some noticeable banding on the left side of the hood, try to avoid sandwiching many layers layers of different shades with only a single pixel between each of the shades, that is what is called banding, and is generally considered a malpractice.

Now, you really should try to make it on your own following the guide lines from the edits, good luck.

What you should notice now is that with the new shading of the folds the light on the body part do not match the hood part. For instance, compare it with eishiya's edit, and you will see you had the light direction matching correctly the first time (which is the reason no one pointed it out before), so if you changed it, do it on the hood also, which would be almost completely darkened in this new angle. Also try to keep the undithered pattern consistent and remove the same amount of dither from the hood. There is nothing stopping you from doing a little dither, more subtle, maybe near the lower parts of the outlines as a boundary to a third darker shade of folds, perhaps, but if you decide to do it, try to make it consistent across the whole piece

True, with dither only 3 shades can cover all possible angles, although the problem would remain that should north-south slopes and top-right diagonal walls ever superimpose each other they would be indistinguishable without an outline:

 However, I am not a fan (or very competent with) dithering myself. I wouldn't dither large areas and full surfaces to represent an intermediate shade for instance, unless in order to give it a texture. On isometric tilesets, extensive 1x1 dithering would also worsen the readability of the borders of surfaces, I think, because it would interfere with clarity of the 2x1 diagonals with the alternation between single pixels of the two colors used to dither.

Dear diary, today I learned Rhombicomboctahedrons are things, and everybody renders or take pictures of them with frontal, centered or uniform diffuse light to avoid serving as reference.







But not all is lost, and apparently the triangular faces can be darker than their neighbor slanted faces, if renders are to be trusted: