Well, I finally hauled my arse over here in order to comment!
You know how impressive I find this piece - his tortured expression, too many wrinkles for a man his age, his eyes so lustrous yet so full of pain, and the amazing copper-bronze tones you've used to show the reflected light of the curse. Incredible.
I would dearly love to see this Severus' face in repose, too. He's close to how I imagine him.