Well, 'Jotaro's Redemption' is an interesting jotaro fanfic. It shows Jotaro dealing with the consequences of his past actions and trying to make amends. 'Jotaro in the Parallel World' is also quite cool. In this fanfic, Jotaro is transported to a parallel universe where things are very different from his own world. He has to adapt and find his way back. Then there's 'The Secret of Jotaro' which uncovers some hidden aspects of his character.
In a well - written jotaro crossover fanfic, the world - building has to be on point. If it's a crossover with the Lord of the Rings world, the details of Middle - earth need to be accurate and immersive. Jotaro's Stand abilities need to be balanced in the new world. For instance, if he's in a world of magic like in the Chronicles of Narnia, his Stand can't be overpowered to the point where it breaks the story. The fanfic should also explore the cultural differences between Jotaro's world and the crossover world. For example, if he's in the Inuyasha world, how does his modern - day sensibilities clash with the feudal Japanese - like setting? The relationships Jotaro forms in the crossover world should be complex and add depth to the story.
One possible theme could be adventure. Maybe jotaro and kakyoin go on a journey together on horseback, facing various challenges along the way. Another theme might be friendship. The horse could act as a symbol of their bond, something they take care of together and through which their relationship deepens.
First, you need to really understand Jotaro's character. Know his personality traits like his stoicism, his intelligence, and his loyalty to his friends. Then, come up with an interesting plot. It could be something related to his Stand, Star Platinum. For example, you could write about a new ability that Star Platinum discovers. Also, make sure to include some of the other characters from the Jojo universe to make it more authentic.
One popular jotaro crossover fanfic is 'Jotaro in the World of Harry Potter'. It combines the cool and stoic Jotaro with the magical world of Hogwarts, creating interesting interactions and new storylines. Another is 'Jotaro Meets the Avengers', where he teams up with superheroes to fight common enemies. There's also 'Jotaro and the Dragon Ball Universe', which imagines how he would fare in a world full of Saiyans and powerful fighters.
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.
A unique aspect is the different character dynamics. For example, interactions with other characters like Joseph might change. A female Jotaro could bring a new emotional depth to relationships.
One possible plot could be that Kakyoin and Jotaro come across a mysterious horse in their adventures. This horse has some special abilities related to the 'Stand' powers in 'JoJo's Bizarre Adventure'. They then have to figure out how to handle this horse and how it might be related to their mission.
Well, finding 'jotaro x kakyoin horse fanfic' might be a bit niche. However, you could also check out some JoJo's Bizarre Adventure fanfic communities on Reddit or Discord. There, fans often share and discuss their favorite fanfics. Maybe someone has come across or even written a story about jotaro and kakyoin involving a horse in those communities.