You should stay away from solid black outlines, especially if the object isn't black.  Instead use a darker color that's close to what you're using.  Also, for a sword you need to think about the kind of material a sword is.  It's metal so you should try to put some shiny streaks rather than giving it a random gradient.  1-2 main shades might do it for the whole blade

I made a quick edit to show you what I mean:


Hope that helps

thanks for the edit! i like what you did there, but the black outlined one was just the first version.
i went from line art -> filled in line art (what you edited) -> the good version that's on the original pic.

the shine you did on the blade doesn't really match the style i was going for though. 

i'll keep trying different stuff to see what i can come up with.