Dreamfever I think will have to do with the dream world people go when they sleep. Like in the story of Jane and Aedan. In the booklet KMM mentions something about this with Mac and her dreams.
I feel that the dark figure is somehow connect to this as well. That maybe the dark figure is unable to hurt her until she fully awakens her memory on her past, which she has blocked out. And her dreams are the key to this.