Let's move on to the second aspect of the mission statement: the inner demon. This is the means by which the characters maintain their individuality. Characters in Neuromancer did it through drug addiction, death wishes, isolation, extreme body modification, and sheer insanity. There wasn't anyone in that book who was just a little quirky. They were either faceless and forgettable, or they had something really wrong with them. So we need something similar for this game, something to give players the power stay themselves, but to do so in a way that breaks them.
Okay, so there's clearly got to be some kind of disadvantage tied to a character's inner demon, but again, it needs to be mechanical. The 90s were strewn with RPGs that introduced disadvantages that you were just supposed to role play, and while they were a big step in the direction of thinking about your character's personality and not just his combat stats, too often these disadvantages were banks of points that you got for free and proceeded to ignore in actual play. A character's inner demon needs to inflict a mechanical penalty to the character, while at the same time it needs to provide some mechanism by which a character can increase his punk rating.
So, each character has a demon, defined along theme appropriate lines. This gets a variable rating (um... 1-5 maybe?) defined by the player at the start of each adventure (I'm still assuming this being a Shadowrun game, that it will be built around specific missions/jobs). The rating determines how hard the demon is kicking at that particular time. Sometimes it's nice and placid and behind the scenes, and sometimes it's a raging beast. Take for example the demon "drug addict." At a rating 1, the character might feel the occasional pang, but he can pretty much white knuckle his way through the job. At rating 5, he's jonsing for a fix constantly. Time that should be spent gathering intel on the team's target is spent instead scoring a fix and blissing out. He's walking into firefights high, and he's going through withdrawal when they need him driving the getaway car.
A character's Edge is equal to his Punk + Demon. Yes, this does mean that the more messed up a character is on any given run, the better he'll be performing, but we're going to chalk that up to him being less distracted by all the trivialities of the world. Demons are an aspect with only a downside. The GM can compel the aspect, just as any other, and you are free to resist if you like. However, it costs you a number of points equal to your demon rating to avoid succumbing. When it's really kicking, you're going to be spent just keeping it at bay, and if things get too rough, you are going to give in.
That should make the "brokenness" of cyberpunk characters a more front a center thing in this game. With rare exception, players want their characters to be good at what they do. That means high edge. But that high edge comes with a price, and I'm willing to bet people will pay it, which hands the GM the tools necessary to help players explore the dark parts of their character's unique snowflake of a personality.