Rey will be losing her soul. This will basically answer a very old question of hers whether or not she, as a synthetically made creation, even has one, so it'll both be great for long-term development and potential threads with a soulless Rey.

I don't plan on her going fully violent and attacking people willy nilly, but she will probably just be more like an empty machine who doesn't feel or care about anything. To her, that is pretty scary on its own, as well as probably to her friends/fam when they see her this way. I'm thinking maybe Rey will try to leave the city to try and get her soul back, but she might not do that willingly. If anyone wants/can drag her out, then A+ to that.

Meanwhile Ravine will be, for lack of a better phrasing, losing her control over her reaper abilities and be turning into a demonic force known as a Shedim (more details on them here).

During the first few days she will be fine, but later on Ravine will be more or less be amping up the spook factor by haunting the crap out of people. Think hardcore J-horror shit, like Ju-On or The Ring. Some people she might make more of a living hell out of than others, depending on the severity of the haunting you'd like. She could do something as minor as calling someone and making scary gutteral noises on the other end to her crawling out of your closet and chasing you around your apartment building. That sounds like fun, right?! Fear should be so happy. Who doesn't love a good supernatural spook?

This also means that she will be a risk to other spirit types as well -- such as Atem who she will attempt to get her ghostly mits on and devour like a tiny delicious spectral cupcake.

I have a lot of ideas for haunting scares, but I'm open to suggestions as well!