i really think the pose and lines are looking great. and the sword looks fine with all the jaggies on the side, makes it look war torn. you could just sharpen the tip with some anti-aliasing.
as far as colors, you should consider using sel-out to really add contrast in between the tones, like on the chest-plate for example. the hair could have more of a hair-like texture and not necessarily realism, more like ariel from the little mermaid. anyway, keep at it man, i'm really digging this.
btw, do NOT look up jayce on google images...eww