You can try looking on Archive of Our Own (AO3). It has a large collection of Homestuck fanfics, including ones about Nepeta and Karkat. Just use the search function and type in 'Nepeta x Karkat' within the Homestuck fandom section.
One common theme is friendship. Since Nepeta and Karkat are both characters in Homestuck, their relationship often starts as a friendship in fanfics. They might support each other through different challenges in the Homestuck universe.
I'd recommend checking out 'The Adventures of Nepeta and Equius' on Archive of Our Own. It has a great plot that really brings out the best in both characters.
One of the great things about Nepeta x Equius fanfics is the potential for character growth. We might see Equius becoming more in touch with his emotions through his interactions with Nepeta. And Nepeta could also learn about boundaries and self - control from Equius. Fanfic writers can take these two characters in many different and creative directions in their stories.
One great 'Homestuck Gamzee x Karkat' fanfic is 'The Bond Between Them'. It really delves into their complex relationship, showing how their different personalities interact. The author does a wonderful job of portraying Gamzee's laid - back yet somewhat unpredictable nature and Karkat's more uptight and easily - flustered self. It's full of heart - warming moments as well as some comical exchanges that are true to the Homestuck spirit.
Karkat is highly emotional. His passionate outbursts and strong opinions can create interesting dynamics in a 'Karkat x Reader' fic. He's not afraid to speak his mind, which can lead to both humorous and intense interactions with the reader.
Another theme could be redemption arcs. Maybe Eridan has done something wrong in the story's context and Karkat helps him to become a better person. It can be a really interesting way to develop their relationship within the fanfiction.
The popularity also comes from the fact that both Gamzee and Karkat are well - developed characters in Homestuck. Their backstories, quirks, and growth throughout the original story give fanfic writers a lot to work with. Writers can explore their relationship from different angles, such as how they support each other during difficult times, or how their friendship might turn into something more romantic. This allows for a wide variety of fanfics that can appeal to different tastes within the fandom.
The exploration of Nepeta's growth as a character is also a common theme. As the Homestuck story progresses, Nepeta has her own character arc. Fanfictions may delve into her development, how she overcomes challenges, and how she changes over time. This can include her becoming more self - aware or learning to better interact with those around her in different situations.
You can try Archive of Our Own (AO3). It has a large collection of Homestuck fanfictions, including those about Eridan and Karkat. Just search for 'Eridan x Karkat' in the search bar and you'll get a bunch of results.