The gun needs a dark wash to show off the grooves. The black cloth needs a highlight or two. And the armor needs more layers. Oh, and the space underneith the stone base needs to be filled in cause it just looks like it wants to pop right out.
break up the green with lime mixed to yellow or thinned out yellow, highlight it all up, maybe some stroneger highlights on the robe, black wash carefully placed on the storm bolter, blacken the ends of the barrel so they look like they shot alot, very tiny txt letteriing on the honor badges or purity seals rather, in a light brown. one hair brush and run thin lines of black ink or dark wash through all the angel and eagle wing emblems. i think the strong part is his face so far, its looking good from the photo.