I was thinking about this, and not addressing the specific difficulty of this map, but a general thought: There are already potions that give you 95% resistance to a few of the main attacktypes. Why not add some more potions in, like potion of poison resistance? paralyzation resistance, etc? IMO, I would rather have potions have 100% resistance than some of the general permanent items have this (ie, like the ring of Life). This would seem to be more balancing than having objects that give permanent immunity (ie, if you still want to keep being immune to that stuff, you need to keep spending money). Adding such potions may help balance out fighters and mages a little, as mages do typically do stuff from a distance so don't need those immunities quite as badly.