Work In Progress - 3D Casual Demon Head

So those reference pictures I posted earlier aren't for show! I have to model the character that was chosen (The demon character to whom many of my latest pictures have been dedicated to) in Z Brush 4r4. No mohawk and pony tail beard on him just yet!

This has been my first experience with Z Brush, I rather like it! This section of the model has taken me over 8 hours to get to this point. I'm currently on Sub division level 3 so I think I can crank in some more detail yet!

Any critique you guys can offer? My lecturer likes how I've progressed so far, he wants me to improve the horns a little, along with the mouth and ears. If you guys want to see it in multiple views just say and I'll take some more screenshots.