Labyrinth Lord was used as a base, with "Wonder and Wickedness" brought into to replace the arcane spells. There's a thing in WaW where trying to cast spells beyond your allotted slots can cause catastrophes. These range from harmless and interesting to game changing.
So there was a murder. There was a southern-style plantation with a bunch of fancily dressed men and women. The party seemed to be a part of them: no armor, no weapons (except the witch had snuck in a dagger).
Turns out they were the murderers, and the person they murdered was a demon. Everyone at the party was a demon. They had been hired to take this poison (one use per demon) and kill them all. They didn't remember who hired them, but they remembered why. They knew that when some was discovered dead, the party would call in a Pyschomancer. His name was Wilhelm, he rode a motorcycle, black leather jacket, and had a sawed-off shotgun. All psychomancers have a truth aura, and they like to dive into people's minds and explore the dungeons inside to extract confessions, memories, whatever else they need. They don't have to dress like that. That's just Wilhelm.
She they knew he would show up and if they didn't remember the murder, they wouldn't be lying. So then they had to kill the rest of the demons while avoiding Wilhelm and not letting the other demons know.
They almost did it.
One demon, called himself Edward (real name is Silent, but they don't know that), had split up with Emily to the master bedroom. She led him into the bathroom. He locked the door behind them. They rolled initiative. She won. She tried to circumnavigate the situation, but it didn't work. He tried to dominate her. It worked.
"Kill your friend," he said. Coleen had come looking for her after successfully killing the demons that were around her by convincing them to have an orgy (I asked, "what percentage chance do you think these demons are lustful?", and we thought 90% was fair). Emily comes out and stabs Coleen with her hidden dagger. Coleen pleads with her and gives her another chance at a save. Emily snaps out of it.
They rush the bathroom and Edward is stepping through a portal that closes behind him. Jordan's on the opposite side of the house and Wilhelm is coming to investigate screaming he heard (from the demon orgy). Jordan sneaks out behind him after he passes her room. She tells the "indentured servants" that the demons are dead. They yell and run.
(Again, I asked "what percentage chance to do you think Wilhelm thinks this is more important than a few yelps?" and we settled on a number.)
Wilhelm went back outside and saw the fleeing servants. This is against the law. He pulls out his shotgun and takes chase. Jordan flees into the woods.
Emily and Coleen head out to Wilhelm's motorcycle. Emily reaches into the Nothing and pulls out a spell, rolling for a catastrophe. Nothing serious happens, just some storm clouds and a little rain. They ride off hoping to meet up with Jordan on the road.
That was the end of the first session. As for how the Witch becomes a bird...well that comes later.