This is an idea for a demon-themed RP. It's based partly on previous ideas I've had, and inspired by the music video to a song by the band Kamelot.
The music video appears to tell the story of two boys - presumably brothers - who accidentally cause the death of a girl, probably their sister. The one actually responsible then appears, for the rest of the video, to be haunted by visions of what appears to be an undead version of the girl. I'd like to do a variation on this. The two characters will not, in this case, be related by blood. My character, when still young, caused the accidental death of a girl, and grew up wracked with guilt.
Instead of seeing the ghost of the girl, however, he is eventually visited by a demon. The specific motivations for the demon can be worked out, but presumably she's preying on his doubt and feelings of guilt. He believes the demon to be the spirit of the girl - which she may or may not be. It would like for a strange relationship to develop between the two, where the demon tries to behave as though she has his best interests in mind, cares for him, forgives him - loves him, even. He, in turn, in a twisted way starts to care for her.
What happens beyond this is more open. One possible twist is that my character was not alone when the girl died, and the demon tries to convince my character to murder the other one, promising this will be what will finally set him free.
Whatever happens, I'd like a story full of emotion, intrigue, betrayal - and sex. If this sounds at all tempting, let me know!