Many people have complained that the Assassin is too strong as his opponents never roll a die unless they fight with craft or are characters and attack him.
My idea to weaken him would be to reduce his special ability so that opponents can still roll a die, but only a D3 instead of a D6. That would still help a lot but does not make him overpowered. Now opponents would roll results of 1-3 instead of 1-6, and the average value would be 2 instead of 3.5 (3 or 4).
! Everyone should be gunning for him, as he is about the easiest pickings in the game.