GPT 4 can write decently but it’s either going to be a bit corny or very derivative. Really a LLM is the wrong type of AI for this task. A GAN (a type of Generative AI) built for writing is going to produce a lot better text in terms of creativity and bringing something new to the table. If it’s too out there you could then pass that through GPT to fix any potential language issues or coherency issues (in terms of language, GPT can’t fix plot holes well).