It can start with conflict. Since Jotaro is a hero and Dio is usually a villain, there could be intense battles between them at first. But then, as they learn more about each other, they might find common ground. For example, they could both be seeking a certain power or knowledge.
One idea could be a story where they meet in an alternate universe where Dio is a female. Jotaro is initially suspicious but then finds himself intrigued by her charisma. They could be forced to team up against a common enemy, and during their journey, they start to understand each other better.
The main characters are clearly young Joseph and Dio. Joseph is a character with a strong will and unique abilities, especially his Hamon. Dio, on the other hand, is a powerful vampire with his own set of formidable powers.
Perhaps a plot point where the power dynamic between them shifts unexpectedly. Maybe Joseph discovers a weakness of Dio that no one else knew, leading to a very tense and exciting confrontation. In fanfiction, this could be something completely new and creative that the author invents.
He could meet his past allies in a different context. For instance, he might encounter Kakyoin or Polnareff when they were just starting their journey. Maybe he could also run into Dio at a time when Dio was still plotting his rise to power, which would create a very tense situation.
The JJBA manga is indeed finished. It had a great journey and wrapped up with a satisfying conclusion for fans. However, there's always the possibility of spin-offs or related works in the future.
A dio graphic novel is a form of visual storytelling that combines elements of both art and narrative. It typically has a sequential art style, with panels that tell a story. The art in a dio graphic novel can range from highly detailed and realistic to more stylized and cartoonish. These novels can cover a wide variety of genres, such as superhero stories, historical fiction, or personal memoirs.