Callous as it is to say, the Deep Caverns are consistently built up in the game as being a place where the most dangerous wildlife and factions go to have their big fights. It's the home of the Faceless and even the Tchortists themselves tell you that, only the very best of the Rassophores are sent down there to guard Tchort, and it's influence is the only thing that even allows them to hold onto their territory. Every time dialogue comes up about the DC, it's laden with synonyms for deadly, lethal, and for turning your life span into the measure of minutes.
Therefore, by the time you get to the DC, you should be in the habit of making many, many hard saves. Especially in regards to this near game-length slew of warnings you've been given. The sheer scale of events surrounding the Institute of Tchort should be a good enough sign that some major shit is going to go down, and you should be very well prepared before you make further moves.