A possible plot for a 'Fate Stay Night Frozen Crossover Fanfiction' is that Rin Tohsaka travels to the world of 'Frozen' to study the unique magic there. She meets Elsa and they start to exchange knowledge about their different forms of magic. Elsa is intrigued by Rin's gem-based magic and Rin is fascinated by Elsa's ice powers. At the same time, some of the darker forces from 'Fate Stay Night' follow Rin to 'Frozen' and try to take over Arendelle, forcing Elsa, Rin, and their newfound friends to fight together to protect the kingdom.
One idea could be that Saber from 'Fate Stay Night' gets transported to the world of 'Frozen'. She could be mistaken for a powerful sorceress. Elsa might initially be wary of her but then realize they both have a connection to magic that they need to control. Another plot could involve Shirou being in Arendelle and using his skills to help build things, while also getting caught up in the drama between Anna and Hans. Maybe he could use his projection magic to create something that helps save the day in Arendelle.
A cool 'fate stay night crossover fanfiction' idea might be a crossover with 'Final Fantasy'. The different classes and magic systems in Final Fantasy could blend well with the Fate universe. For example, a character from Fate could learn the job classes from Final Fantasy. Also, a crossover with 'Persona' could be interesting. The Velvet Room and the concept of personas could be integrated into the Fate world, adding a new layer of mystery and power to the story.
One interesting plot idea could be that the Servants from Fate Stay Night end up in the Naruto world. For example, Saber could team up with Naruto. Saber's noble and just nature would blend well with Naruto's determination to protect his village. They could face off against common enemies like Orochimaru, who might be interested in the power of the Servants. Another idea is that the concept of chakra in the Naruto world could interact with the magic in Fate Stay Night. Maybe a mage from the Fate universe tries to study chakra and finds a way to combine it with their own magic system, creating a whole new type of power. A third plot could involve the Holy Grail War taking place in the Hidden Leaf Village. The ninjas would be both intrigued and cautious about this strange new event, and the Servants would have to navigate the politics and unique environment of the village while fighting for the Grail.
Perhaps Shirou from Fate Stay Night could find himself in the Re Zero world. He might use his skills as a mage and his determination to help Subaru in his quests. Their different outlooks on life and combat could lead to some interesting character development as they learn from each other.
A possible plot for this crossover fanfiction could be centered around the concept of the 'ideal'. In Fate Stay, each Servant has an ideal they fight for, and in RWBY, the characters also have their own beliefs and goals. So, a story could be crafted where the characters from both universes have to compare and contrast their ideals. Maybe some of the Fate Stay characters are confused by the concept of the Grimm and the Huntsmen/Huntresses' role in RWBY, while the RWBY characters are intrigued by the Servant - Master relationship in Fate Stay.
One interesting idea could be exploring different routes for the characters. For example, what if Shirou had chosen a different Servant at the start? Another could be delving deeper into the backstories of the Servants, like revealing more about their lives before they became heroic spirits. Some fanfictions also play with the concept of alternate universes, where the rules of the Holy Grail War are changed completely.
One idea could be to have Naruto characters participate in the Holy Grail War. For example, Naruto himself could be a Servant, perhaps with his chakra being a unique form of mana. His skills like the Rasengan could be reimagined as powerful Noble Phantasms. Another idea is to put the Fate Stay Night characters in the Naruto world. They might have to deal with things like ninja clans and the politics of the hidden villages while also trying to find a way back to their own world.
Well, perhaps in this crossover fanfiction, the power systems of both could merge. For example, the magical abilities of the Fate Stay Night characters could combine with the Freezing characters' abilities. Let's say Saber's Excalibur could be enhanced by the energy manipulation skills of a Freezing character. And there could be a love triangle between a Fate Stay Night male character, a Freezing female character, and another character from either universe, which adds a lot of drama to the story.
In a Fate Stay Night Skyrim crossover, Archer could be summoned by a powerful mage in Skyrim. Archer would find the concept of the Thu'um fascinating as it's a form of magic he's never encountered. He could start exploring Skyrim, looking for ways to use his own abilities in conjunction with the local magic. He might get involved in the civil war between the Stormcloaks and the Imperials. His strategic mind could help whichever side he decides to side with. And when the dragons return, he could use his Unlimited Blade Works to create weapons specifically designed to fight dragons, like blades that can pierce dragon scales more easily.
One of the most interesting pairings would be Saber and Elsa. They are both strong female characters with powerful magic. Saber could teach Elsa about combat and leadership, while Elsa could show Saber how to better control her magic in a more natural way. Also, Kristoff and Lancer could be an unexpected but interesting pairing. Lancer's pride and Kristoff's down - to - earth nature would create some fun interactions.
Another plot could involve the heroes from Fate Stay Night being transported to the world of the Shield Hero. They then have to adapt to the different rules of that world, like the wave system. For example, Saber could try to fight the waves using her Excalibur, but find that it's not as effective as she thought due to the different magic systems.