Well, it's finally crept into my head.. After, gee, how long? probably over two years of being a lurker on this list.. ( Yeah, I'll add in my two cents every now and then, but sometimes it isn't even worth that much *grin*) I finally have caught the bug and think I am ready to run something.. I even have an idea for a story and wanted to send it to you guys, since no one I know (thankfully) knows anything about Kult.
Okay.. Here's the story so far.. It's not completed.. and I want to get any and all responses from you guys (preferably via email rather than this list..) Right now, I have a bunch of the background.. or rather, I have the story that will explain why he is like he is, or whatever.. well, bear with me..
The PC will be in his early or mid twenties.. pretty much keeps to himself, though he does have friends, and possibly even a love interest, he just doesn't let anyone get too close. Lately he's been feeling like something is missing, or very very wrong.. very guilty.. but he can't put a finger on what or why. His work is suffering, his relationship (if any) is suffering.. He needs to find out why..
WHY:
The PC, we'll call him Jimmy, Once had a younger brother (by three years) who he used to have to play with (you know.. mom tells you to bring your younger brother with you etc..). They used to play in the forest behind their house. There was a small stream which led into a grate which led further down into a river or pond of some sort.. Anyhow, they used to play Pirates (or whatever) down there, with 'John' (The younger brother) always 'locked' up (in the drain behind the grate) as a prisoner or some such thing like that. As Jimmy was returning from searching for buried treasure (mind you at this point he is 9 or ten years old) He could hear John yelling for him.. Not just yelling.. but screaming out of fear and terror. As Jimmy rounded the bend to where their 'ship' was, He could see John reaching through the grate trying to get through to freedom, but to no avail.. The last thing he saw was John's arm being pulled back through the grate, and then darkness. He crept closer to the grate.. trying to get a handle on what was going on, he opened the grate.. slowly.. and leaned in closer.. there was nothing there but emptiness.. emptiness and a rotten smell.
After this event, Jimmy runs home, tells his parents what happened the police are called, etc.. The disappearance is ruled a kidnaping and they spend a few years searching but nothing is ever found. The case and the kid is forgotten.. buried beneath uncaring, unfeeling parents and a brother who feels it is his fault.
So this is how I see it...
All this guilt and fear is pushed deep deep down and forgotten.. well, at least until the present day. And Maybe the Guilt has created a place where his brother still 'lives' (or exists) and also blames Jimmy for what happened to him and is trying to get him back for that.. I'm not sure what will trigger the return of this guilt. Maybe the smell of whatever it was in the grate, or I dunno.. I need some ideas here kids.. I also need to know what would have been in the grate.. I've got books and all here.. but I want your input as well.
Alright.. that's it for now..
I hope to get a lot of advice and ideas from you guys to help me unfold the story..

I think it would be rather good if the PC was actually the one who killed his younger brother. Or maybe he didn't kill him, but has kept him in a hole or a cave somewhere near all these years. The thing is, he doesn't know it himself. First of all, the reason why he killed/kidnaped his brother was pure jealousy. He wanted to be the one his parents loved, and no one else. So he tricked his brother to some unknown place, and there he killed/trapped him. Then he went home to the house and said the things as written above. But he says that they happened in a totally opposite direction than they really did. So the police search in the wrong place, and the PC gets all the attention. But the guilt of what he's done creates another personality, one who actually believes the things he told the police and the parents. So this, new and innocent personality start to take over, leaving his dark, evil self far away. But unknown, even to himself, he sneaks away occasionally to see to his brother (or, to get rid of the body). And this continues throughout the teenage years and into his twenties. But now, with nightly journeys to either tend to his brother (who, by this time, has become a gibbering insane wreck of a human) or to find other children in his brothers age to kill, starting to take their toll, his world is starting to collapse.
So he needs to find out why he's so feeling so guilty. Maybe he's starting to find dirty, bloody clothes at home, without knowing where they came from (whenever these things happened before, he would deny it and put it in a dark corner of his mind, where it will never be remembered). Maybe he's starting to have horrible nightmares (which are actually real memories from the nightly visits to his brother or the murders he commits) and start to recognize surrounding areas. Maybe someone finds his brother and he's in the papers. Since he's completely lost his mind, and cannot talk, no one knows who he is. Maybe the PC starts to recognize the descriptions of the brutal murders of children as he reads about them in the newspaper.
How will he handle the truth about his own horrifying past? What will he do?
Well, that's about it. Sorry that I might have raised more questions than I have answered, but at least I've given something to thing about.

The example that you give sounds like the point where the mental balance is about 250 ? Where the 2 parts of your soul/mind/body split and become equal opposites
If your not afraid to do it and you don't feel that it would ruin the game, perhaps you could do a sort of reawakening of what has happened to him before ( this follows on from the post by Jonas with the killing of his brother).
The human mind can forget things so well it makes me ... um .. er ... drat what was I doing at that time ........