Even the pools of water in the Slugmarsh are saturated with the madness of the fallen, turning even the PC's minds against themselves.
Pools of Insanity (CR 10)
Even though the water is still and stagnant, it seems very much alive.
Type: magical; Perception DC 23; Disable Device 16
Trigger location; Reset 1/day
If a PC gets within 30' of a pool, they begin to see faces and other images in the pool. A DC 27 Will Save is required to look away. If a PC does not look away, the images coalesce into a mirror image of the PC. Then, a common item the PC holds, either a weapon, holy symbol, wand, etc begins to writhe and shimmer, as if melting or covered by insects. The PC develops an subconscious obsession with the item. Whenever it is used, the PC must make a DC 14 Will Save or become fascinated by the item for 1d6 rounds. This acts as the manic condition as described in the Advanced Topics section in the Pathfinder Game Mastery Guide. Once afflicted, a PC cannot be afflicted for at least one day. Additional mania may be gained after one day, though.