I’d love to see characters with low sanity nudge the world into a greater vortex chaos and insanity.
A low sanity character could see strange temples/ritual sites/corrupted pyramids/sacrificial alters/blood lakes popping up on the world map, eldritch horrors traveling through the void through buildings/vehicles whatnot, shadows dancing in the dark, bloody footprints appearing and vanishing right before the player’s eyes, a plethora of ghosts/phantoms might just appear surrounding the player for a tick before vanishing, horrific towering striders with quivering tentacles meandering through the mists, going into bathrooms/basements/etc may just lead you into a hellish realms, and other horrific events. These are just a few events I’ve thought of.
He or she might even be possessed. The screen turns black for a few seconds and he/she wakes up in another nearby location with hellish/eldritch/tainted/corrupted drawings all over the place. These could be drawn in blood/etched/sprayed/clawed/chiseled/etc onto various objects/vehicles/walls/floors depending on what’s available.
Items reappearing in the inventory after it’s been dropped. Bodies moving around off screen or gathering together in strange patterns on the floor. Map legends are different from the onsite location(heading to the strip club ends up with you at the fire station. Both got poles right?).
Controls reversing for a few turns. Lights turning off then turning back on.
Maybe the entire day was just dream/nightmare. You go to sleep and spend a day doing whatever you want. Then strange shit occurs and something kills you. BAM you wake up in the same spot you went to sleep at. There’d be some signs at first something in the details… like a spoon spawning right next to you when you first wake up. Maybe it’s bent or twisted? Maybe the spoon is still there when you wake up for real. Or is it real?
A random portal appears and a stream of cultists pour out of it. They organize themselves into a parade and march towards another location/portal while chanting/screaming/howling while blood/smoke/etc drips/sputters out from them.
A creature might just hunt you down and beat you senseless just to steal an item. Gollum anyone? You hear a scream and see a hideous creature sprinting for you. It’s babbling nonsense. After fighting with it for a bit you notice it’s focused on (item).
Following the bloody footprints might just provoke the being that created said prints into a furious rage. Who likes being followed? Certainly not him/her/it.
Some event/horrors are real while others are just figments of the mind. Some of them are passive until you get too close or you look/examine them. Curiosity killed the cat after all. Of course some could have delicious rewards that causes people to tempt fate. Some events/creatures could be warded off with religious chants/scriptures. Bonus effect if the character has religious trait/clothes/trinkets.
Remember when you gaze long into an abyss the abyss also gazes into you. The more you interact/get close to/talk with/attack these strange event/creatures the more they pay attention to you.
Probably better off as a mod to be honest. Well this was a fun comment. Had a lot of fun ideas to think of and write down. 