Do you mean a route between Erika and the demon? Yes, I have in mind to do it, what I don't know is at what point in the story. Maybe it won't be in the first season.
I feel like it already started. They're always touching and holding eachother. I have two ideas:
1. Demon takes out her frustration at not getting enough energy from other people by having some fun with Erika
2. Erika starts getting flirty dialogue options with her which causes the demon to get flustered and more protective. Maybe going along with her decisions without complaining suddenly and getting super clingy.