I'm sorry, but I can't recommend 'lemon' fanfics as they often involve inappropriate and adult - like content. However, you can look for general 'hiccup x elsa' fanfics on fanfiction websites like Archive of Our Own or FanFiction.net.
Their relationship might start with curiosity. Hiccup would be curious about Elsa's ice powers and Elsa about Hiccup's connection to dragons. As they interact more, they start to respect each other's abilities and personalities. This mutual respect turns into friendship, and then gradually into love. The news of the baby would strengthen their bond as they now have a shared future to look forward to. They would support each other more, with Hiccup protecting Elsa during her pregnancy and Elsa using her powers to help Hiccup in his adventures.
Well, one interesting idea could be their exploration of each other's magical abilities. Hiccup could be fascinated by Elsa's ice powers and they could learn from one another about controlling and using their unique gifts.
The best elements would include their respective powers. Hiccup's dragon - training skills and Elsa's ice magic can create some really cool interactions. For example, they could use their powers together to fight off an enemy or to create something beautiful for their kingdoms. Another element is the cultural clash and subsequent understanding. Hiccup's Viking ways and Elsa's royal Arendelle upbringing can lead to interesting situations where they learn from each other.
First, understand the characters well. Hiccup is from 'How to Train Your Dragon' and Elsa from 'Frozen'. For a married fanfiction, start with how they meet. Maybe it could be in a magical land that combines the worlds of Berk and Arendelle. Then, focus on their relationship development. Show how they learn about each other's strengths and weaknesses. For example, Hiccup's ability to bond with dragons could amaze Elsa, and Elsa's ice powers could be useful in Berk's cold climate. Finally, add some conflict, like a villain who wants to break their marriage or a misunderstanding between them to make the story more exciting.
In a 'anna elsa x mother fanfic', the mother could be a central figure in resolving the conflicts between Anna and Elsa. Maybe she was lost long ago, but through some magical means, she comes back in a form to guide them. This could add a new layer of emotional depth to their story, as they deal with both the joy of having their mother back and the challenges of following her advice in a world that has changed since she was last there.
There could be. A lot of fan - fic writers like to create crossovers between different universes. Elsa from 'Frozen', the Creeper from Minecraft and Spiderman are all very popular characters, so it's possible that someone has written a story involving them. However, it might not be very common given how different their worlds are.
One possible antagonist could be a jealous sorcerer. He might be envious of Hiccup and Elsa's relationship and the power that their unborn child is said to possess. So he tries to harm Elsa during her pregnancy to stop the child from being born. Another could be some of the traditionalists from their respective kingdoms. They don't approve of their relationship and see the pregnancy as a threat to their old ways. They might try to separate Hiccup and Elsa, which would put Elsa's pregnancy at risk.
One possible plot could be that Hiccup, while on a journey with Toothless, somehow gets transported to Elsa's world. He stumbles upon Elsa as she is trying to control her powers in a difficult situation. Hiccup, with his experience dealing with dragons, offers her a different perspective on handling her powers. They gradually grow closer as they share their stories and in a moment of deep connection, they share a kiss.
One great 'Merida x Hiccup' fanfic is 'A Meeting of Two Worlds'. It beautifully weaves their different cultures together. The story has them meeting by chance in a magical forest and then going on an adventure to save both their kingdoms. It's full of action and also some sweet moments between them.