I was reminded of this by the trailer for a side-scrolling platform game set in ancient Greece - in the style of ancient Greek pottery decoration.
When helping set up a Dark Ages: Vampire game online one thing I did was illustrate all the major NPCs - but one thing I planned to do was attempt in-character illustrations showing them in suitable medieval (and in some cases earlier) art styles. This idea never got past a few preliminary sketches, but I think it would have been cool to build up depictions of specific characters across time in the styles of the era.
Maybe something I should do with the 1500-year-old elder in my current V20 game...
The 11th century mosaics in Torcello cathedral, Venice, include a very early monstrous version of Satan... a friend or enemy of the Giovanni?