This sculpt is a pretty straightforward depiction of Hazlik, though the Elizabethan ruff collar is a touch that might not be used now. Hazlik's tattoos are actually sculpted onto his head, which really makes it more like scarification, but also reminds the painter that he does have tattoos. Were I painting a custom figure to represent Hazlik, I'd probably just use a fine technical pen to draw in the tattoos, much as is done on many modern figures who sport them now.
One amusing moment in painting this figure was trying to figure out if Hazlik's blue eye was on his right side or the viewer's right side (which would be his left eye, actually). The Gazetteer portrait shows the former and Stephen Fabian's original Black Box portrait shows the latter!
The paint scheme itself is pretty straightforward, using a nice bright red for his robes and gold to add to a somewhat fiery quality. After deciding that that strange little ball in his hand was, in fact, a fireball, I found a fairly interesting paint to use on it. Reaper Miniatures, in their paint line, makes a metallic color called Fire Glow, which is effectively a mix of orange and gold. While I preferred to paint the torches of Horg and the Village Mob with non-metallic yellows and oranges, Fire Glow gives a nice touch to magical flames or to items that are glowing with heat such as coals. I highly recommend it to painters, who may also want to investigate Reaper's colored metallics (though you can probably simulate those by mixing appropriate inks or thinned non-metallic colors into silver).