The Doom Guard texture is good, but doesn't have much detail. Illidan's wings would suit well. I may help you animate them properly if you want.
Then, what you should do is replace the blurry Blizzard armor with a detailed one (I recommend textures such as Orc Warlock, Doom Guard, Felguard and maybe some fel orc textures). Put some flame in the eyes and don't forget the teeth (I suggest Mannoroth's).