Most difficult class to play through on Impossible Difficulty?
 

For some reason I never feel like playing through the game again after completing it.

So I want greatest challange to increase the length of fun/planning I can extract from this game so I would appreciate advice on which is the hardest character class to complete the game on Impossible Difficulty.

OK I answered this myself as the game manual states the Soothsayer is the most difficult class to play with...