One way to do a Keyblade in anime worlds crossover fanfiction is to first establish the rules of the Keyblade within the context of the anime world. For example, if it's a Naruto crossover, you might decide how the Keyblade's magic would interact with chakra. You could also create a story where the main character from the anime discovers a Keyblade. Maybe Naruto himself stumbles upon a Keyblade during one of his adventures and has to learn how to use it to defeat a new kind of enemy that's immune to normal ninja techniques.
In a Keyblade in anime worlds crossover fanfiction, a crossover with Code Geass could be fascinating. The Keyblade wielder could be involved in the political intrigue of the Code Geass world. Maybe the Keyblade has the power to break the Geass's control on people. Another concept is a crossover with Fairy Tail. The Keyblade could be seen as a very powerful magical item in the Fairy Tail guild, and the wielder could go on quests with the Fairy Tail members, using the Keyblade's abilities to defeat powerful dark mages.
Start with a bang! Have the keyblade wielder suddenly thrust into a new and strange world without warning. For example, they could be in the middle of a battle in their own world, and then in a flash, they're in a post - apocalyptic world filled with zombies. This immediate change will grab the reader's attention.
One idea could be to have the keyblade wielder from the original Keyblade world end up in a high - fantasy world like Middle - earth. The keyblade could be seen as a powerful and mysterious weapon, and the wielder might have to team up with characters like Aragorn to fight against Sauron. Maybe the keyblade has unique powers that can help turn the tide in battles against the orcs.
Some characters from other franchises that are popular in keyblade crossover fanfiction are Cloud from Final Fantasy. His cool demeanor and powerful sword - fighting skills (which can be translated to keyblade skills in the crossover) make him a fan - favorite when combined with the keyblade concept and Kingdom Hearts - like settings.
In keyblade crossover fanfiction, a cool concept is the creation of new keyblade forms inspired by the combined elements of different franchises. This might involve a keyblade that has the magic of a certain wizard from one series and the physical design elements from another. It allows for a lot of creativity in terms of both appearance and power.
I'm not sure specifically which one is the 'worlds largest crossover fanfiction' as there are numerous crossover fanfictions out there. It could potentially be a very long and complex work that combines elements from multiple different fictional universes like combining characters from 'Harry Potter' and 'Star Wars' in a single story, but without more context, it's hard to determine exactly.
In the world of 'Bleach', Ghost Rider's powers would be very different. His chain could potentially be used to bind Hollows or even Soul Reapers if he were to be an antagonist for a while. His Penance Stare might have an interesting effect on Hollows, perhaps forcing them to relive all the sins they committed while alive. However, it might not work on Soul Reapers in the same way as they have different moral compasses.
One possible scenario in a Naruto Keyblade fanfiction could be Naruto obtaining a Keyblade. He might use it in a unique way, combining his ninja skills with the power of the Keyblade. For example, he could infuse his chakra into the Keyblade attacks, creating powerful and unexpected combos.
Golden Frieza's role in crossover fanfiction worlds is quite diverse. He could be a catalyst for change. If he enters a world full of heroes, his evil nature might force them to unite in a way they haven't before. Or he could be a source of knowledge, having come from a different universe with different technologies or magic systems. His presence always shakes things up, whether it's through his brute strength or his devious mind.