I love it! It's so clean and shaded so well, it's like it's popping out at me!
The only part that stands out in a not-so-good way is the bottom shading on the eye. The brush that you used had a LITTLE too hard of an edge, but nothing else on your beautiful picture does! Maybe you used an eraser with a hard edge to tidy it up and it did somethin'?
Again, this little comment shouldn't make you feel like this ENTIRE picture is terrible, because in all honesty, it's quality is astounding! It's just that tiny portion I'd watch out for next time.. (because clearly, you know exactly what you're doing, and are very capable of doing so! c: ♥)

Ahhh, thank you!! *w*

Ah, my reasoning behind that is mostly because it'd be a shadow around the edge of the eye, because Yamask always looked like it'd be a little bit bug-eyed to me. I use a watercolor tool for most of my shading and it's good at blending with lighter strokes and creates that harder looking shading when you don't spread out the strokes. I usually use harder shading against edges like that where it looks like the shadow would be more defined. That's just my thought process on it though, thanks for the feedback!

Sorry if that wan't the most appropriate response, it's not all too often I get constructive criticism |D