Theirs is a relationship full of passion and conflict. Their love is intense, which makes it interesting. And the fact that they are often caught up in the grand schemes of fate in the Fate universe adds an extra layer of drama.
A common theme could be the clash of different mythologies. Since Sigurd and Brynhildr are from Norse mythology (in the context of Fate) and RWBY has its own kind of lore, seeing how these different mythological elements interact is often explored. For example, how their powers might be perceived in the RWBY world of Huntsmen and Grimm.
I'm not sure of specific 'Sigurd and Brynhildr Fate RWBY Fanfiction' off the top of my head. But you could also try reaching out to RWBY or Fate fan communities on social media platforms. Reddit, for example, has dedicated subreddits for both fandoms. Post a request there asking for good fanfictions involving these two characters in the RWBY world. People in those communities are usually quite helpful in sharing their favorite reads.
In some fanfics, it's a love story. Writers might focus on the moments when they first meet and fall in love. They might describe how Sigurd's heroic deeds attract Brynhildr, and how their connection is so strong that it defies the odds. However, it's also common for it to become a tragedy as the darker elements of the Fate universe start to play their part.
Siegfried would be an obvious choice as they have a deep connection in the Fate lore. Their relationship can be explored further, like how they deal with their past issues together. Another good character to pair with Brynhildr is Rin Tohsaka. Rin's strong - willed and intelligent nature can contrast and complement Brynhildr's more stoic and traditional warrior self. It could lead to some interesting interactions and storylines.
A good plot for a Brynhildr Fate fanfic could be a time - travel story. Brynhildr could be sent back in time to a crucial moment in her own history. She could then have the chance to change things that she regretted in her past. Or, you could write about Brynhildr falling in love with a character who is not from her original story. This would create a lot of interesting drama as she tries to balance her new feelings with her duties as a Servant. Also, a story where Brynhildr has to train a new and inexperienced Servant could be quite engaging.
It's not appropriate. In the fanfic world, 'lemon' is a code for sexual content. 'Brynhildr in the darkness' is a story that can be enjoyed in a clean and family - friendly way, and adding 'lemon' to it goes against that. So it's not a proper form of fan - created content for public consumption.
A 'brynhildr in the darkness' fanfic might be about the adventures or the daily lives of the characters in that world. But the 'lemon' part is a bit concerning as it usually means sexual content. Ignoring that, it could be about how the characters deal with the challenges in their world, like the mystery of the powers they possess or the relationships they form with other characters in a more platonic or emotional sense.
The 'A Song of Ice and Fire' fanfic with Sigurd could be one where he discovers a long-lost secret that changes the course of the story. It might also be a tale of his rise to power and the challenges he faces along the way.
One aspect to consider in brynhildr in the darkness fanfiction is the character development. Writers often explore the complex personalities of the characters more deeply than in the original work. They might give more backstory to Brynhildr, for example, her life before the events of the main story. This can add a new layer of understanding to her actions and motives.