Trampis I like your strong lighting, it's just the composition feels a little off balance. Some whites in the lower right corner, and maybe a bit over Thor's left (our right) shoulder would even things out I think.
Fco, great composition - the monster faces are fun, and I really like the area of Thor's hammer and outstretched arm. And yeah, what Dann said about whiteout. You can still ink over it as long as you're not too rough with it.