This is absolutely fabulous and scary. The dark plain background, simple and good. The way you gave him defined hard shading an many of his edges and points were sharp really signifies his strength and malice. I loved they eyes, the way the green glow come out a little and onto his eyelid and teh purple smoke fades naturally backwards was done very well. His armor's metallic texture looks great, the reflections on it look awesome. His white sharp ferocious teeth are frightening as well. Especially with that little bit of gum sticking out. The bright light coming in from the top right was a nice touch too. To me it seems he is looking at the Crystal heart, or an incoming Celestia laser beam(you know, during his defeat?)
Love it, sorry it took so long to comment, been busy.
Thank you for your comments seriously. Your thoughts are also good for his state of mind. But I prefer that Rays to the upper right corner is revenge of hope. He watched the light, and he would revenge.