Have a look at this new skin for arthas, I also made frostmourne a lava blade but I couldn't be bother putting it in. Even though this is a colour change it sure as hell didn't take me 30 seconds, more like two hours (The colours had to be done by hand, shade by shade).
You should add more dark colors, like black and greyish areas, and change the color off his hair to black or something other than the regular Arthas hair, and he looks a little cartoonish with all the bright red and yellow action going on, don't be afraid to use maroon and darker colors
You need to skin the whole thing to make it look good. The silver metal parts need to go. You need to shade more also. I love the volcano on the book lol