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.
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. Imagine a female Hiccup in a male - dominated Viking society. She might struggle to be taken seriously as a dragon rider, which creates an interesting dynamic. Another is the friendship - to - more trope. She could start as friends with Astrid or other characters and then develop deeper feelings over time. And of course, the underdog story, where she has to prove herself against all odds, just like the original Hiccup did in the movie.
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.
One popular theme is the combination of different kinds of magic. The ice magic from Frozen and the dragon - related magic in HTTYD. Another theme could be friendship across different worlds. Characters from HTTYD like Hiccup and those from Frozen like Anna forming an unlikely alliance. Also, the theme of discovery, as the characters from one world discover the wonders of the other world.
One popular trope is the 'transfer student' where a character from another series enrolls in U.A. High. For example, a character from Naruto might show up with their unique abilities, creating interesting interactions with the BNHA characters. Another is the 'power swap' trope, where BNHA characters get the powers of characters from a different universe and have to adapt. And the 'alternate universe' trope is also common, like a world where heroes and villains have different alignments or the BNHA world has a different social structure due to the influence of another fictional world.
Well, the 'team - up' trope is quite popular. Imagine Batman and Sherlock Holmes working together to solve a mystery that spans across their respective universes. Then there's the 'love - across - universes' trope. Characters from different universes fall in love, which creates a lot of interesting drama and conflict, especially when they have to deal with the differences in their worlds. And the 'lost - in - a - new - universe' trope where a character has to find their way back home while navigating the strange new rules and inhabitants of the crossover universe.
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.
One popular trope is the 'fish out of water' situation. For example, when a character from a high - tech sci - fi world ends up in a more primitive or magical crossover world. Another is the power - up trope. A character might gain new abilities when crossing over into a different sci - fi universe. And the team - up trope is also common, where characters from different sci - fi franchises join forces to face a common threat.
One popular trope is the 'fish out of water' scenario. For example, a character from a historical drama suddenly finds themselves in a modern - day drama setting. It creates a lot of comical and interesting situations as they struggle to adapt to new technologies and social norms.
The 'enemies - to - lovers' trope is also common in Draco Malfoy crossover fanfiction. When he crosses over and meets a character from another world, they start off hating each other but gradually fall in love. This can be really exciting to read, especially when they have to overcome their differences in values and backgrounds.