To write such a fanfiction, you could begin by deciding on a central conflict that ties in with the themes of both. Maybe a powerful enemy threatens both Berk and Westeros, forcing them to work together. Also, pay attention to maintaining the tone and style of both franchises to make the crossover feel seamless.
You could start by taking the magical creatures and adventure from 'How to Train Your Dragon' and combine them with the complex politics and power struggles of 'Game of Thrones'.
You might find crossovers where characters from both universes interact in unexpected ways. Maybe a dragon rider shows up in Westeros or a Game of Thrones character discovers a dragon egg in the land of Berk.
You could have a story where characters from How to Train Your Dragon find themselves in the world of Game of Thrones and have to navigate its politics and dangers.
One popular theme is the further adventures of Hiccup and Toothless. Writers often explore new lands and challenges that they might face. For example, they might encounter a new type of dragon with unique abilities.
Well, when Hiccup is a dragon in fanfiction, it could be because of an ancestral connection or a mysterious experiment. This could open up new storylines and allow for exploration of his identity in a completely different way. Maybe it's a way to show his ultimate empathy and unity with the dragon species.
Hiccup in the fanfiction typically trains by forming strong bonds with the dragons first. He shows them kindness and respect, and then gradually introduces training exercises that are fun and challenging for both him and the dragons.
Hiccup would likely approach it with enthusiasm. Since he loves his dragons and his adventures, he would be eager to see how others imagine the world of 'How to Train Your Dragon'. He might find some fanfictions that give him new perspectives on his own life and relationships. Toothless, being a dragon, might not understand all the words but would react to the emotions in the stories. If the fanfiction shows a happy moment between him and Hiccup, he might get excited and start making his little happy dragon noises. Astrid would probably analyze the fanfiction carefully. She would look for any inaccuracies in how her character is portrayed, especially when it comes to her skills as a dragon rider and her relationship with Hiccup.