I like, I don't see anything wrong with the mouth it just looks like he was captured in the pic as he was getting ready to say something, perhaps he is speaking some of the words to his spell or something, if he is using a spell that is. The only really minor nit pick that I would have is that the fireball looks slightly like it is casting a shadow back over his forearm. If you did this in Daz or Poser you could just drop an orange /reddish point light in behind the fireball so that it casts light up his arm as a fireball would do I am not sure how you would do it in Photoshop.
What a show-off! All them fireworks just to light a cigarette! Character looks great, distinctive, strong detail and I like the new lighting too. Nice touch of Pulp style too. Good stuff!