its too much of the same thing, if you are going to do a thing like this, all molten crap, you have to have something that makes it more interesting. like chunks missing that glow fire, you have to optimize the stuff as much as you can, make sure the shading is right, and above all, becouse this is hard to shade, make the fire in the areas that would normally be highlighted on the skin, more brighter, smooth some orange and yellow into it to make it more interesting.
also, as the eyes are a main focus on anything, you should distinguish them more from the rest, i'd say smooth in the orange and yellow in the cracks around that area, and make the eyes the brightest, adding some infernal-green into the eyes. that should make it less dull.
EDIT: read the other comments, larger cracks and especially larger plates in the chest would do this good.