It's likely about the adventures of the Kamen Rider Dragon Knight. It might include battles against villains, the exploration of the Kamen Rider's powers, and the relationships with other characters in the story.
Character development is a big part. When you bring Naruto and the Kamen Riders together, you can see how they grow and change. Maybe Naruto becomes more tech - savvy from his interactions with the Kamen Riders, or a Kamen Rider learns the importance of teamwork like in Naruto's team. And the new relationships that form, like friendships or rivalries between the characters from the two different franchises, add depth and intrigue to the fanfic.
Ryuki is often very popular. He's the main character in the original series, so he's a natural focus in fanfiction. His journey and his growth as a rider make him an interesting character to write about.
Another interesting concept is a crossover with a fantasy world like Middle - earth from 'The Lord of the Rings'. Imagine Dragon Knight finding himself in Middle - earth and having to adapt to a world without his usual technology. He could form an alliance with the Fellowship to fight against a new evil that has the power to corrupt both their worlds.
You can try looking on fanfiction websites like FanFiction.net or Archive of Our Own. They usually have a large collection of fan - made stories for various shows, including Kamen Rider Dragon Knight. Just use the search function and type in the relevant characters' names to see if there are any stories featuring Kit and Maya.
One idea could be exploring an alternate universe where the riders form different alliances. For example, some of the more antagonistic riders team up against a common threat that is far more powerful than any single rider. This could lead to interesting character development as they have to put aside their differences.
First, decide on the other universe or story you want to cross over with. It could be a game, a movie, or another TV show. Then, think about how the two worlds will interact. For example, if it's a crossover with a video game world, consider how Kamen Rider Dragon Knight's powers will function in that digital realm.
Another interesting aspect is the cultural clash. Naruto comes from a world of ninjas with its own values and traditions, while the Kamen Rider world has a more modern, technological - based society. How the characters from these two different worlds interact and learn from each other can be very engaging. For example, Naruto might be amazed by the advanced machinery in the Kamen Rider world, and the Kamen Rider characters could be intrigued by Naruto's spiritual and physical ninja training. There can also be plot points about how they work together to overcome challenges that neither could face alone.