So I was GMing my monthly DFRPG game and this happens:
Our game is set right before Summer Knight. We've just finshed a major story arc and I wanted to run a third season Episode 0 to get a feel for how people felt after the drastic changes that happened in our last session. I'd only lightly preped so I had to wing a monster based on my players description. This is pretty normal for Fate. Plus once you get over the learning curve as a GM it makes the system a lot more fun to run.
The set up: the parent's of The Morrigan's Eyes, For Now(TMEFN) are in the burn unit at Presby in PGH. Their house caught fire in a highly suspect manner shortly before pc's were going visit. As they walk to a waiting room I have them roll alertness then ask the person with the highest score to tell me what they saw. So now I have an official looking lady doctor with no shadow. My thoughts went to some kind of powerful emotional vampire so I flipped open Our World to Lord Wraith's entry and reskined it on the fly.
The Practicing Angel(PA) managed to detect my new shadowless monster was up to no good. She botched her roll to do the "accidental" bump into the monster. This is where another of the fun mechanics in Fate comes into play. Instead of failing she chose to succeed at a cost. The creature realized PA was on to her and as a reaction triecd to drain the PA in a suprise round before the group could react. Instead of lust I picked mental exaustion as the emotion the creature fed on
Luckily The PA has high mental fortitude and only took stress. Now comes the rolls for initiative. At the top of the order is TMEFN, who decides she absolutly had it. In the process of finding a loophole out of her bargain with the Morrigan she'd discovered she'd been set up big time by someone other than her boss replace her centuries old wizard predecessor. Possibly since TMEFN was four. And someone yoinked her soul out of her body and held it hostage to get an unspecified favor from her boss. All of this happenec in the last 72 hours in game time.
THEFN suprises all of us at the table lands a fantastic social atack with presence. TMEFN goes into full emisary of power mode complete with change of hair color and the apperance of a blood red Medieval gown. Marching up to the creature she shouted "That's it, I've had it! You stop that right this instant!"
The thing is the creature dose. It filled it's moderate consequence with This is Above My Pay Grade and conceded the fight. Upon interagation we learn the creature is an anonymously hired paid assasin who is pissed off that she was unknowingly sent after the family of an Emissary of power. Mostly because the fee is several orders of magnitude higher and failure to disclose puts her client in breach of contract. It told us You may call me "Kira" then became a shadow and disapeared to go hunt down and eat her former client.
After the creature I made up on the fly dissapeared, another of my players, Modern Professional Celtic Hero(MPCH), makes a great Lore roll to identify this thing. Now I have no more of a clue what this thing is than MPCH's player does. So I flip the question back to him. After a moment of thought he comes up with this "Let's see it eas accedentaly created or summoned by an active fandom forum on the internet. Um, it's sort of the opisit of a dream eater. It eats your conciousness while you're awake. Lets call it a Lucidityphage."
At this moment we realized we just created an in-game creepy pasta assasin that came to life. Probably from the SCP. Also now i need to dust off my rusty writer skills and actualy give this creature a srory so I can stat it out properly.