There are several notable panels throughout the 'JoJo's Bizarre Adventure' manga where Jotaro and Dio face off. One of the most intense ones is during their final battle.
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.
In this fanfiction, perhaps they could have an epic battle against a common enemy. Jotaro with his Star Platinum and Jonathan with his Hamon could combine their powers in a unique way.
DIO could be a likely villain. Since he has a long - standing feud with the Joestar family. He might try to take advantage of the situation where Jotaro and Jonathan meet to cause chaos and try to defeat them both.
Well, they might have an epic showdown at first. Jotaro with his Star Platinum and McCree with his Peacekeeper. But then they could realize they have a common enemy and team up. Maybe they'd exchange stories about their different worlds.
A plot twist might be that Jotaro loses his Stand abilities temporarily and McCree has to protect him. Or perhaps they find out that there's a traitor among the people they thought were their allies in this fanfiction world. This would force them to re - evaluate their situation and who they can trust. Also, it could be that a powerful artifact they were supposed to protect actually has the power to control them, and they have to fight against its influence.
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.
You might be interested in the book "The Substitute Messenger of the School City." It tells the story of a person named Xio who met with misfortune while on a plane. After that, he transmigrated to a city that was 30 years ahead of science and accidentally obtained a substitute. There is also a plot to defeat DIO in the story. I recommend it to you. I hope you like this fairy's recommendation. Muah ~