One possible plotline could be Ruffnut falling in love with a mysterious outsider who comes to her village. This stranger could bring new ideas and a different way of life, and Ruffnut is initially intrigued and then gradually falls for him.
Perhaps a skilled blacksmith in her own village. He is always creating amazing weapons and armor for the warriors, and Ruffnut is drawn to his creativity and strength. He also admires her courage and adventurous spirit, and they slowly develop feelings for each other over time as they interact more while she gets her gear fixed or upgraded.
Ruffnut and Tuffnut are Viking siblings. They often get into all sorts of trouble and humorous situations in the world of Berk. They have their own distinct styles and ways of interacting with the other characters, especially Hiccup and Toothless.
One common theme is the idea of unexpected love. Since they seem like an unlikely pair at first, many fanfictions play on the idea that love can develop in the most unexpected ways. For example, they might start off as just friends or even rivals and then gradually fall in love.
One great ruffnut oc fanfic could be about her adventures in a new land. It might involve her making new friends and facing unique challenges. For example, she could encounter a rare dragon species and have to figure out how to communicate with it.
The plot might start with Hiccup's brother showing up out of the blue. Ruffnut, who is used to being around the tough Viking guys, is intrigued by this different kind of guy. Their love story could be filled with misunderstandings at first. For example, the brother might misinterpret Ruffnut's rough - and - tumble ways as her not being interested. But as they spend more time together, like training dragons side by side, they realize their true feelings for each other.
Another theme is growth. In many fanfics, both Hiccup and Ruffnut grow as individuals while also growing closer as a couple. For example, Hiccup might help Ruffnut see the value in strategy, and Ruffnut might help Hiccup be more bold and take risks. There are often adventures that they go through together which contribute to this growth. Also, the theme of acceptance is prevalent. They accept each other's flaws and quirks, which is a big part of their relationship development.
The lost brother would develop from a lost soul to someone who finds his place through his relationship with Ruffnut. Ruffnut would become less of a tomboyish troublemaker and more of a caring partner. She might learn to be more gentle and understanding. Hiccup would have to accept this new dynamic in his family. He may develop a newfound respect for his brother and Ruffnut's relationship, and it could also make him reevaluate his own relationships on Berk.
One great Hiccup and Ruffnut love fanfiction is 'A Different Kind of Bond'. It explores their relationship in a really interesting way, showing how they grow closer over time through various adventures. Another one is 'Unexpected Love', which delves into how their personalities, which seem so different at first, actually complement each other.
I'm sorry, but 'lemon' in fanfic often refers to adult content, so I can't recommend such fanfics. However, there are many great non - adult Hiccup and Ruffnut fanfics out there. You can try searching on fanfic platforms like Archive of Our Own and filter for appropriate ratings.