One popular 'castle crossover fanfic' could be one that crosses 'Castle' with a detective story from another universe. For example, a crossover with Sherlock Holmes. The characters from 'Castle' might interact with Holmes and Watson, creating interesting scenarios where Castle's more light - hearted detective style clashes or complements the deductive reasoning of Holmes.
First, decide which two universes or stories you want to cross over with 'Castle'. It could be another detective show, a book series, or a movie. Then, think about how the characters will interact. For example, if you choose a crossover with a superhero story, consider how Castle would react to having superpowers around or how the superhero would view Castle's detective methods.
Well, it could be a really magical story. The Last Unicorn's grace and mystery could blend with Howl's flamboyant magic. Maybe the unicorn could find its way into Howl's world, and they could go on an adventure together. The unicorn might be both fascinated and a bit confused by Howl's moving castle, and Howl would surely be intrigued by the unicorn.
He could react with anger. After all, if he has feelings for Beckett, seeing her with someone else like Vaughn might make him furious. He might lash out at both Beckett and Vaughn without really understanding the situation.
Well, usually when Castle leaves Beckette in such fanfics, it causes a lot of emotional turmoil for both. There could be moments of self-reflection for Beckette, and maybe Castle realizes his mistake and tries to come back. It all depends on the author's imagination!
I haven't read this particular 'castle 4x07 fanfic' specifically. However, in general, a fanfic based on a specific episode like this might expand on the relationships between the characters. It could delve deeper into the emotions that were only hinted at in the show, or it could create alternative scenarios that didn't occur in the original episode.
A Castle and Beckett baby fanfic could be about their journey into parenthood. It might explore how they adjust to having a baby in their lives. For example, Castle could be super excited and start writing new stories inspired by his new family experience, while Beckett might be a bit more cautious and protective.
An 'arranged castle fanfic' is likely a fan - created fictional story that involves some sort of arranged situation within the setting of a castle. For example, it could be an arranged marriage between two characters in a castle, or an arranged alliance. Fanfic, short for fan fiction, is written by fans of a particular work, often a book, movie, or TV show, and they use the existing setting and characters to create their own stories.
One popular 'castle crossover fanfiction' might be one that crosses 'Castle' with a detective show like 'Sherlock'. In such a story, Castle and Sherlock could team up to solve a complex mystery. The different deductive styles of Castle and Sherlock would create interesting interactions.
You could start by imagining how the characters from both stories might interact. Maybe the unicorn stumbles upon Howl's castle and their adventures begin from there.