Mustrum_Ridcully
Legend
On a side note I suppose it you use save or die monsters you could put in heavy hints that they would be around, putting in clues like crumbled stone statues or a ritual book describing a summoning of Bodaks which the PC's could use knowledge roles to predict they would be facing these things and prepare, but then that would take the point of the effect away as the PC's with the correct protections would just walk straight through it.
The good thing here is that it rewards players intelligence and ability to understand clues or search for them. The bad thing is it invalidates the entire power. Instead of leaving clues there might be a Medusa or Bodak around the next corner, why not use clues to advance the plot, tell us something about NPCs, the history of the setting, the big bad plan of the enemy?
Using your smarts to cast Raise Dead before opening the door to the Bodak room is so... technical and cold. Using your smarts to figure out that it was actually the Blacksmith that is allied with the Orcus Death Cult and is just using the Gnome as a scapegoat sounds more compelling.
Of course, it's not an XOR-relation - you could have both. But - I also like fast-paced action, and having to find all the clues to one me for the guaranteed TPKs if I am not forewarned stands in the way of it.