Ulquiorra Cifer

I'd say it is creepy (in a good way)!
I like that you stick to minimum of colours it helps to achieve integrity of the piece.
It is a good idea to use broader brush for first application of colour. It helps to organize shapes and values and to avoid "hairy" look of what is not supposed to be hairy. Especially while hair itself is not detailed.
I'm not sure if the eyes were intended to be "pasted" over the face creating unnatural and rather scary gaze. Unless it was done on purpose, you should not have put those huge anime-styled eyes on a face that looks absolutely flat and has no eyebrows. It is really a good idea to try realism and then to stylize your drawings.
The half of the helm looks incomprehensible. If it is made of metal, it should reflect what is around. And it has to be tied to the head somehow. One more point is the hole(?) on his neck. You should have either work it out better or ignored this detail at all.
I have no idea who this character is and what he is supposed to look.

I was not sure whether I should write it in comments or here, feel free to delete this message if you feel uncomfortable with it. And again I strongly advise you to try realistic drawing/painting.

Good luck!