One idea could be an adventure where Elsa teams up with a dragon (to tie in with the dragon master idea). Maybe the dragon is from a far - off land and Elsa has to learn to communicate with it to save Arendelle from a new threat.
One idea could be that Elsa is a powerful sorceress from a far - off land who arrives in Westeros during the War of the Five Kings. She could use her ice powers to control the weather and influence battles. For example, she might freeze the moats of castles to make them easier to invade or create ice bridges over rivers.
You can try fanfiction websites like Archive of Our Own (AO3). There are tons of fan-written stories there, and you're likely to find some great Elsa fanfics. Just use the search function and type in 'Elsa' to start exploring.
One idea could be that the OC is a powerful mage from a far - off land who comes to Arendelle during a time of new danger. The OC meets Elsa and they initially have a bit of a clash due to their different ways of using magic. But as they face the new threat together, they start to understand and respect each other more. Eventually, they combine their magical powers to save Arendelle and in the process, form a deep friendship or even more.
One plot idea could be that Anna discovers a new magical power within herself and Elsa helps her learn to control it. This could involve a journey through the Enchanted Forest where they face various challenges together and their bond grows stronger as a result. Another idea is a time - travel plot where they go back in time to prevent a past event that had a negative impact on their relationship. They could also face a new villain who is specifically targeting their sisterly bond, forcing them to work together to defeat the foe.
A possible plot could be that there is a lemon - themed festival in Arendelle. Hans, who has returned after his banishment, tries to win Elsa's forgiveness during this festival. Elsa is initially skeptical but as they both participate in the lemon - inspired games and activities, they start to develop a new relationship that is different from their previous encounter.
One idea could be that they are on a quest together in a magical world. They have to overcome various obstacles and their relationship grows stronger as they rely on each other's skills.
Well, a possible plot is that Elsa's pregnancy is a result of some magical encounter. As she progresses through the pregnancy, she starts to notice that her unborn child has an affinity for ice magic even before birth. She then decides to create a special, safe place made of ice for the baby to be born in. And also, she could have dreams about the future of her child, which guide her in making decisions for Arendelle's future as well.
She could interact with Daenerys Targaryen. They are both strong female characters with special powers. They might initially be rivals, both vying for power and influence in Westeros, but then realize they can achieve more by working together. For instance, Elsa could use her ice powers to cool down the hot deserts that Daenerys has to cross with her armies.
Well, it could be about Spiderman getting transported to Elsa's world. Maybe he helps Elsa deal with some new threats in Arendelle using his spider - powers. For example, a new villain emerges who can freeze the whole town and Spiderman's agility and web - slinging skills are needed to stop this villain from causing more harm while Elsa tries to control her powers to unfreeze the people and places already affected.
A possible plot is that Elsa's kingdom is threatened by a force that is related to the same kind of threats the Avengers face. The Avengers hear about her and her powers and travel to her world to offer their help. Along the way, they learn about her backstory, and she learns about their heroics. Together, they combine their powers to save her kingdom and in the process, Elsa decides to join the Avengers on some of their adventures in their own universe.