Looks aweswome, as usual Omega. I really like your style of drybrushing, leaving the black showing and all.
To answer the question about drybrushing, you coat the figure first, usually black depending what your going for, then dip your brush in the paint and wipe almost all of it off on a rag or something leaving almost nothing on it and brush it over the surface back and forth leaving barely any paint on it. It'll build up over several passes, that real metal look Omega666 achieved is a prime example of good drybrushing technique and as you can see you can do it with regular colors. With regular colors you usually use a darker shade then go lighter but it can be done in reverse, artists preference really.
Other than that, Omega made the best Universe Galvatron I've seen, props man.