A badass ninja with modern equip, what else could you want in a picture? (yeah, robots).

Seriously now, this is one of those pics you see in your devwatch page that you want to open without even knowing what it is about. I was kinda unfamiliar with this character, but you described him well, not to mention the background music that adds to the whole pack.

Art-wise, I must point out the way you used shadows and lightning. As we can see in his mask, there are some bold lines that define the dark areas, but they are somewhat blurred. With that, not only you give the mask that... artificial look, but it also makes the whole picture look smooth witout looking silly (you know what I mean, gaussian blur and all those other effects).

The stylized armor reminds me of Samurai Jack, not because of the theme, but the use of single straight lines to define different elements, giving complexity to a simple lineart. The choice of colors is good too, I just think that his arms and neck are a bit exposed (specially the neck, since we're talking about ninjas).

On the downside, I'd point out the background. The tv-screen effect is a little overused in this one, and the choice of typography for his name and your gallery's URL could be a little better. I'd suggest working out simple background that refer to the character a little more, so we could get further into the description of your awesome characters!