There might be a fanfiction where Arataka Reigen somehow gets involved in the Akatsuki's plans. Since he is so good at bluffing, he could try to infiltrate the Akatsuki and end up in all sorts of crazy situations. Or perhaps a story where he helps Naruto train his Rasengan in a really strange way, like using his psychic - like skills (even though they are mostly fake in his original series) to enhance Naruto's chakra control.
To write an 'arataka reigen naruto fanfiction', start by doing research on both series. Know the rules of the Naruto world, like chakra and jutsu. For Reigen, understand his way of talking and his motives. You could start with a simple idea, like Reigen being hired to help a ninja village with a'spiritual' problem. As you write, let the characters develop. Maybe Reigen will learn some real skills from the Naruto characters, or vice versa. Also, use vivid descriptions to bring the Naruto world to life in your story, whether it's the Hidden Leaf Village or a battle scene.
Well, one characteristic is the blend of different universes. Since sans and reigen are from different fictional worlds, fanfics often play with the idea of how these two very different worlds collide. For example, in some, the magic or powers from each world interact in unique ways.
A common theme is friendship. Their relationship is often explored in depth, showing how they rely on each other. For example, in many fanfics, mob looks up to reigen for guidance.
One interesting dimple x reigen fanfiction could be about them going on a supernatural adventure together. Maybe Dimple uses his ghostly powers to help Reigen out of a tricky situation in a haunted house, and in the process, they develop a deeper understanding of each other.
There's also 'The Unspoken Connection' which is really good. It focuses on the unspoken understanding between mob and reigen. The author does a wonderful job of portraying their unique dynamic.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of various fanfictions, and you can easily search for dimple x reigen ones using the search bar. Just type in the relevant tags and browse through the results.
One popular sans x reigen fanfic is 'Crossed Realms'. It weaves an interesting story where the two characters from different universes interact in unexpected ways. It has great character development and a unique plotline.
Reigen survives throughout the manga. The story doesn't involve his death. The plot focuses on his adventures and interactions without that tragic event.