Well, in a crossover, the ponies could have a ship of their own, like a flying ship made of clouds or something really magical. They could cross paths with the pirates during a storm. The ponies' ship could be immune to some of the bad weather effects because of their magic. And then they team up with the pirates to find a hidden treasure that requires both the pirates' seafaring skills and the ponies' magic.
One interesting crossover could be the use of magic in the world of Pirates of the Caribbean. For example, a wizard from Harry Potter might find themselves on a pirate ship and use spells to fend off sea monsters. Another could be the pirates trying to steal magical artifacts from the wizarding world.
One good crossover could be Percy using his water - controlling abilities in the world of Pirates of the Caribbean. For example, he could help Jack Sparrow's ship escape from a powerful maelstrom by calming the waters. Another idea is Percy teaming up with the pirates to fight against a common sea - based enemy, like a giant sea monster that威胁 both the demigod world and the pirate world.
The ponies' personalities can be adapted to fit in. For instance, Rainbow Dash with her adventurous spirit could be like a young pirate eager to prove herself. She could learn sword - fighting from the pirates and add her own flying skills to their adventures.
A great crossover could involve a battle between the magic of MLP and the power of Pokemon. Imagine Twilight Sparkle using her magic against a powerful Pokemon like Charizard. Or perhaps the Mane 6 team up with a group of Pokemon trainers to fight a common enemy. They could combine their strengths, like Rarity using her fashion skills to create cool outfits for the Pokemon trainers while they battle. It would be a really unique and exciting story.
One idea could be a crossover between MLP and a popular fantasy series like Lord of the Rings. Ponies could take on the roles of hobbits, elves or dwarves in an adventure to save Equestria from a Sauron - like villain. Another could be a crossover with a superhero universe, where ponies gain superpowers and fight against evil forces. Maybe a crossover with a classic fairy - tale world, like Wonderland from Alice in Wonderland, and ponies have to navigate through the wacky and strange world.
There might be a fanfiction plot where Elizabeth Swann, instead of being a damsel in distress at times, becomes a powerful pirate captain in her own right. She could lead her own ship and crew, and have adventures that cross paths with Jack Sparrow's. For example, she might be on a quest to find a magical artifact that can control the seas and has to outwit other pirates and sea monsters to get it.
The Kraken in Pirates of the Caribbean fanfic can be a major plot device. For example, it could be the main obstacle that the protagonists have to overcome. Maybe it has been unleashed by an evil character to stop the heroes from reaching their destination. It also adds to the overall atmosphere of the story, making it feel more like the dark and dangerous world of pirates where there are all kinds of threats lurking in the ocean.
In some fanfics, the Hulk might befriend Fluttershy. It's an unexpected pairing but it works. Fluttershy's gentle nature could potentially calm the Hulk down when he's angry. And the Avengers would be introduced to the magic of Equestria, like the Elements of Harmony which could be a key factor in defeating a common enemy.
A crossover might involve the characters from MLP getting trapped in the Tokyo Ghoul universe. The ponies would have to adapt to this new and dangerous world. Fluttershy, with her gentle nature, might initially be terrified of the ghouls but then try to befriend them through her kindness. Rainbow Dash could use her speed to outrun the ghouls and help the other ponies escape from dangerous situations. It would be a really unique take on both universes.
Some pirates in the fanfic could attempt to communicate with the Kraken. This could be through some kind of magic or ancient knowledge. Maybe there's a character who has a special ability to understand the Kraken's behavior or even make it follow their commands. However, this would be very risky as the Kraken is a dangerous and unpredictable creature.