Well, one way could be to immerse yourself in the fictional world they belong to throughout the day. When you sleep, your mind might carry that over into your dreams. Also, try imagining scenarios with them right before bed.
One way could be to re-read or re-watch the story featuring the character right before bed. Focus on their details and personality. It might help your brain incorporate them into your dreams. Another approach is to have a discussion about the character with friends and keep them on your mind throughout the day.
Just let your imagination run wild. Think about their personalities, looks, and backstories. Let those details come to you naturally.
Start by giving them clear goals and motivations. It helps make their actions and decisions more understandable and engaging for readers.
I don't know as I haven't read the novel. It could be a young protagonist who is trying to make sense of their dreams.
One way is to combine common names and tweak them a bit. Like, take 'Emma' and make it 'Emara'. Or, draw inspiration from nature. A character who's connected to the forest could be named 'Sylvan'.
You can have a chat with fictional characters by writing down your thoughts as if you were speaking to them. Or, you could act it out in your mind, picturing their responses. It's all about using your imagination and having a good time with it.
Maybe you have a very vivid imagination and your mind incorporates these characters into your dreams when it's processing and sorting through various thoughts and experiences. Also, if you've been thinking about a particular fictional world a lot lately, that could explain their appearance in your dreams.
One way to find look-alikes for your fictional characters is to study various character archetypes in literature and media. Also, observe people in your daily life and note similarities. Another option is to browse through stock image websites for inspiration.
Well, you could think about using rare and hard-to-detect poisons. Maybe something from a myth or legend. That would add an element of mystery.
I don't think having a fondness for fictional characters alone defines your sexuality. Sexuality is a complex aspect of a person's identity that involves real-life attractions and experiences.