I'm not sure if covering the ears and the hair is needed for a complete shinobi shozoku of a ninja. At least it would make sense for some practical reasons (e.g. to conceal and to protect). Of course hair is easier to depict in an interesting way than a piece of dark drapery (and you did a good job on that)
Also, I think it looks a little more like a guy covered in dark blue ink or oil, maybe because the fabric clings to close to his face reproducing his silhouette to unaltered.
I like style and colors! I think the ear might need alittle reworking though. If I am reading it correctly theres a pin in the ear over his face garment. I think it should be lowered abit to hit the lobe. There should be a larger arc too. Either that or the ear is too small.. Just being anal!
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