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.
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.
Well, Nick Wilde from Zootopia is a sly character. He might be able to adapt to the GTA 4 world more easily than some of the others. He could use his wits to blend in with the criminal underworld, perhaps even using their own tricks against them. In Zootopia, GTA 4 characters would have to adapt to a world where physical strength isn't always the most important factor. They might be surprised at how the Zootopia animals use their intelligence and unique abilities to solve problems and get by in their society.
The characters from Skyrim, like the Nords, are used to a cold and harsh environment. In the world of Game of Thrones, they might find the politics of Westeros very complex. However, their combat skills would be useful. For example, a Nord warrior could easily adapt to being a sellsword in Westeros. The characters in Game of Thrones, on the other hand, would be amazed by the magic in Skyrim. A character like Tyrion Lannister might be very interested in the Dwemer technology and magic.
In fanfiction, the combination of Harry Potter elements with an Aqua Keyblade and Fire can create really interesting scenarios. It could be a story where Harry discovers a magical Keyblade that has the power of water (aqua) and is able to control fire as well. This might lead to new adventures and challenges for him, like facing off against dark wizards who are also after the power of this unique Keyblade.
Maybe through some kind of magical encounter. For instance, he could stumble upon a portal that leads to a world where the Keyblade exists and be chosen by it. It could be that his strong will and desire to protect his friends are what draw the Keyblade to him.
One possible scenario in this fanfiction could be Naruto finding himself in the chaotic world of Harley Quinn and Poison Ivy. Maybe Naruto's ninja skills would be put to the test against the various villains in their world. He could use his shadow clone jutsu to confuse enemies like the Joker or other foes that Harley and Ivy often face.
Well, it could start with a common enemy. There could be an entity that is a threat to both Inuyasha's world and Riddick's. This would force them to team up. For example, a powerful demon in Inuyasha's world has some sort of connection to a dangerous alien race in Riddick's universe. They would have to combine their combat skills, with Inuyasha's swordsmanship and Riddick's hand - to - hand combat abilities.