Gaiden

Overall, like the lone warrior ideal... Ninja??? Hmmm... To be honest, from the POV of a studying Shadow of Eiga (forgive spelling)... This guy's a little too obvious. Clearly, armor on his shoulders (warrior-esque, but NOT ninja)... and clearly either sword or other formidable murder device handle at/about his shoulder (also plenty warrior-esque, and NOT ninja)... The effect still communicates more literally "I think I'm bad-ass, so please, f... with me... PLEASE"... Where the ninja tradition is more literally "Hello, I'm NOBODY of consequence... do as you like." The difficulty with a ninja-esque charater concept is to communicate "bad-ass" with the subtle undertones instead of blaring it out at the top of his/her lungs. Ya' know?
Otherwise, warrior-esque ideal... gratifyingly confirmed. Just a touch more machismo, maybe than a real ninja would prefer to be depicted. Hope this helps as you refine the ideal, and the character. Either direction you would wish to branch... there's a lot of possibility here. You not only can, but WILL get it...