Since it's a fanfic, the author could have taken creative liberties. It might be about a character who is a big fan of 'Enter the Dragon' in the Harry Potter world. This character could introduce martial arts training to other students at Hogwarts, inspired by the movie. And perhaps there are dark forces at play that are related to both the magical threats in Harry Potter and the more physical, combat - based threats in 'Enter the Dragon'.
It might feature a new character who is an expert in martial arts, like a transfer student from an Asian wizarding school, and they could be a main character along with Harry and his friends. They could bring in new ways of fighting dark magic using their martial arts skills.
Since it's a fanfic, it could be really creative. It might tell a story where a dragon has some sort of connection to a swallow, perhaps a magical bond. And then the Witcher elements could be things like Geralt of Rivia being involved. If 'hp' stands for Harry Potter, there could be a scenario where characters from Harry Potter's world end up in the Witcher world and the dragon and swallow play important roles in their adventure, like the swallow leading them to a dragon that holds the key to getting back to their own world or something like that.
It might be a story of an alliance. Say, the lion and the dragon, which are usually seen as powerful and noble in the HP lore, team up against the serpent, which might be associated with dark magic. Or it could be a story of redemption where the serpent, often seen as an evil symbol, is given a chance to change and work with the other two for the greater good of the wizarding world.
It could be Harry Potter himself as he often has to face powerful and symbolic foes. He might be the one to interact with the dragon, the lion and the serpent in some way.
You could try searching on popular fanfic websites such as Archive of Our Own (AO3) or Fanfiction.net. Just type in the title exactly as you have it, 'dragon and swallow hp witcher fanfic', and see if it shows up.
Well, it could also be that the dragon is a misunderstood creature. Harry enters the dragon's world not as an enemy but as a friend. He discovers that the dragon has been misjudged by the wizarding community and tries to bridge the gap between the two species. This could lead to a whole new adventure where Harry uses the dragon's power in a positive way against the dark forces.
Actors entering the HP fanfiction books can have a significant impact on the cultural references within the story. They might bring in modern cultural elements from their own experiences or the real - world acting industry. This could lead to some really interesting crossovers, like a character in the HP world suddenly having knowledge of a famous actor's movie in our world, which could then be used in a creative way to solve a problem or create a new conflict.
In HP (Harry Potter) fanfic, calculations can be used in various ways. For example, when creating magical spells with specific power levels or durations, a writer might do some calculations to ensure consistency. If a spell is supposed to have a certain radius of effect, calculating the area it covers could be important for the plot. Also, when dealing with potions, calculations could be involved in determining the right proportions of ingredients to achieve a desired result.