Legacy of Kain: Soul Reaver for the original PlayStation is still one of my favorite games.
Done in "The GIMP 2.2" with a Genius tablet
12-20 hours ... didn't really pay attention but it was about 3 to 5 hours over a few days.
Heres the concept version that I did originally
[link]And a glimpse at the process of Raziel
[link]