This is truly wonderful! I feel honoured that you partially used my tutorial for some help; thank you.
Anyway, onto this piece...
The drawing on the whole; especially line work wise is very clean and looks superb.
I like the limited palette as well; the reds and brows work well together - you've also edited in those flames really well!
So, overall the piece is great; I really like the shading in the hair; I just think maybe you need to work on adding darker tones to the rest of it; like the skin, and maybe adding more clothing folds and shading to the clothes - I know I go at it a little excessively so I can't really crit. there, but it's just a suggestion.
Okay, I think that's me done - great job!