I actually like Nin's better because Rokkan's looks like his is looking down unlike Nin's which is looking straight forward.
Nin's isn't bad. Actually, it isn't bad at all, I love the shading. But still, its proportions and lineart bug me, so I tried to incorporate nin's shading (among other small things) to my own:
Ha, I was going to reshade Rokkan's! But he beat me to it.
Okay, awesome.
Rokkan, I think your using actually a little too much AA, which is why it looks 3-d to me :/