First, know the characters well from both 'How to Train Your Dragon' (HTTYD) and 'Heroes of Olympus' (HOO). For example, Toothless from HTTYD has unique behaviors and abilities, and Percy Jackson from HOO has his own set of powers and personality traits. Then, create an interesting plot that combines the two universes. It could be something like the demigods from HOO visiting the world of HTTYD and having to work together with the dragon riders to fight a common enemy. Also, make sure to keep the voices of the characters true to their original stories.
One popular trope is the 'fish out of water' situation. For example, a character from HTTYD finding themselves in the world of HOO and being completely confused by the Greek gods and demigods. Another is the 'team - up' trope, where the dragon riders and the demigods join forces to defeat a powerful enemy. A third one could be the 'culture clash' trope, with the Vikings from HTTYD having different values and ways of life compared to the modern - day (sort of) world of HOO.
Once upon a time in the land of Berk, Hiccup was flying on Toothless when a strange magic portal opened. Out of it came Merida from the land of DunBroch. Hiccup was startled but curious. Merida was amazed by the dragons. They decided to team up. Hiccup showed Merida how to ride Toothless and in return, Merida taught Hiccup some of her archery skills. Together they went on an adventure to save both their lands from a common enemy that was using dark magic.
You can start by looking on fanfiction.net. It has a large collection of various fanfictions, including 'hoo hp crossover' ones. Just use the search bar and type in relevant keywords to find what you're looking for.
There's a fanfic called 'Percy Jackson in the Wizarding World'. In this story, Percy finds himself accidentally transported to Hogwarts. His skills as a demigod are put to the test in the magical school, and he has to navigate the complex relationships and rules there. It's full of action and humor.
Next, write your story. Make sure to follow any guidelines the archive might have regarding grammar, formatting, and content. For example, if they don't allow excessive violence or inappropriate language, adhere to those rules. After writing, proofread your work carefully.
First, you need to study the characters and settings of both 'How to Train Your Dragon' (HTTYD) and 'Frozen' well. For example, understand Toothless's character traits in HTTYD and Elsa's in Frozen. Then, think of an interesting plot that can combine the two worlds. It could be about a quest where the characters from both universes have to team up to face a common threat. Also, pay attention to the writing style, keep it engaging and easy to follow.
One popular idea is a httyd and How to Train Your Knight crossover. Imagine the dragons in a world filled with knights and castles. Another could be a crossover with a modern - day setting, like httyd characters in a big city dealing with new challenges. And there's also the idea of a crossover with a fantasy world like Middle - earth, where the dragons interact with different magical creatures.
In HTTYD fanfiction, mythology crossovers can be really cool. Usually, it involves taking elements from different mythologies like Norse or Greek and mixing them with the How to Train Your Dragon world. For example, a dragon could be related to a mythological creature from another culture. It adds a whole new layer of depth and creativity to the fanfic.
In the httyd crossover archive fanfiction, you'll often encounter diverse writing styles. Some stories could be action - packed, with exciting dragon battles in new and unexpected settings. Others might focus more on the emotional and character - development aspects, showing how the characters grow and change through their crossovers experiences.