8 for technique
5 for color composition
The NMM on the sword and the back shows pretty high skill, but the overall color choice is awful imo. Most of all the brown is very offputting and ruins the hightech ninja style. I'd have gone for black to stick to cooler colors, that go well with the grey and blue, broken up by the green.
One other salt of grain would be the grey, that lacks a bit of contrast for my tastes.