The eyes on the wings is a great idea and those fabric pleats are beautifuly drawn, I love it.
The problem that you have with the sleeve might be that they look empty and the pleats on his left sleeve drape across his body, instead of to the outside. I think his shoulders look a little narrow as well, but that might just be an illusion caused by the pleats. Perhaps next time you could perhaps try painting his arms so they don't hang so limp, then they should look much better :)
I luv how you did the wings & the robe. :)