I really like cyberpunk, it was the first non-fantasy setting that I really got into. Don’t get me wrong, I played a lot of others before this, but cyberpunk just had a certain feel to it that was fantastic, and I enjoyed it a lot more than Shadowrun.
Which brings me to one of the main problems with Cyberpunk, well not really a problem, more like just a fact. If the players wanted something beyond the sci-fi setting, for example magic, vampires, supernatural, etc., it meant going to a different setting. Of course it did. I mean there were attempts to get this stuff into cyberpunk, but if you were running a campaign for any amount of time it seemed artificial to suddenly add these elements. It was also time consuming to start up a new campaign.
Instead of starting a new campaign, introducing the features ad-hoc, or going to a new setting, there is fourth solution, and it really fits into the cyberpunk setting without too much difficulty, in fact, once the idea is shown, it might be something that is expected.
The idea relies on two very prominent features of the setting, drugs and humanity loss.
The adventure starts off innocent enough. The characters are at a club, they are celebrating, Either celebrating a victory, or drowning in the misery of defeat. One of their long time friends buys them a round and the night passes into oblivion.
The next day is when things start to become strange. They start to notice that things are different, seeing shadows following them in the darkness. Odd encounters with people talking of omens. Continue to add other supernatural elements. Is a vampire clan trying to recruit them, or a werewolf pack hunting them, or perhaps a wizard council is trying to destroy the world.
Throughout the adventure, make sure that their friend keeps “celebrating” with them and towards the end of the adventure start to sow the seeds of doubt. They attack someone thinking they are a warewolf, but when they find the body its just some cybered up punk. That vampire they tracked down, just a thug parting out people in the alley.
Then when things culminate in the end game, let them know that they have been in a drug induced haze the entire time. Maybe an experimental drug that their friend has been paid to drop in the open market, maybe something used to control people. The characters will eventually figure out that everything they have seen is a lie, caused by the experimental drug.
Of course Vampires don’t exist in Cyberpunk. But drug induced hallucinations spanning several weeks made worse by a lost connection to humanity, that seems about right for Cyberpunk. It gives the players a distraction from their “normal” routine.