One idea could be a crossover with the X - Men universe. The Phoenix Force could interact with different mutants, like Wolverine. Maybe it could enhance his healing factor in a new and unexpected way. Another could be a crossover with the Avengers. The Phoenix Force could be a threat that they have to face together, leading to some epic battles and interesting team - ups. For example, Iron Man might try to create a device to contain the Phoenix Force, while Thor uses his godly powers to try and subdue it.
Well, for a Phoenix Force crossover fanfiction, you could think about crossing it with the Star Wars universe. The Phoenix Force could be seen as a powerful Force - like energy. A Jedi or Sith might be tempted by its power. It could also cross with the Harry Potter world. The Phoenix Force could have an impact on the magic there. For instance, it might enhance the power of a phoenix in the wizarding world, or it could be a source of new and dangerous magic that the characters have to deal with.
A really cool Glitter Force Crossover Fanfiction could involve a time - travel aspect. Maybe the Glitter Force travels back in time to a period when magic was first discovered. There, they meet ancient mages and learn new spells that they can bring back to their own time to use against their foes. Or they could cross over with a fairy - tale world, like Wonderland from Alice in Wonderland, and have to navigate through the strange and magical landscape while still maintaining their Glitter Force duties.
One idea could be that the Lab Rats and Elite Force have to team up to stop a new super - villain who has technology that can neutralize their powers. They start off distrusting each other but as they face challenges together, they learn to work as a cohesive unit.
Another plot idea could be a time - travel crossover. The Glitter Force characters could travel back in time to a point where their predecessors (if there are any in the Glitter Force lore) were fighting a big battle. They could offer their help and in the process, learn more about their own powers and the history of the Glitter Force. This would also allow for some cool interactions between different generations of characters.
A third idea is a time - travel crossover. The Glitter Force could be sent back in time to when their predecessors first fought against an ancient evil. There, they must learn from the past and use the knowledge to prevent a recurrence of the same threat in their own time. They could also form unexpected alliances with the earlier Glitter Force members and discover new aspects of their own powers along the way.
One idea could be exploring the backstory of Rey's parents in more detail. Maybe they were part of a secret Jedi order that was in hiding. Another could be a story about Finn's life before he defected from the First Order, like his training and relationships with other stormtroopers. Also, a fanfiction could focus on Kylo Ren's struggle with the light side of the Force that he tries to suppress.
You could also write about Naruto forming a special force within the Hidden Leaf Village. This force would consist of some of the most talented ninja from different clans. They would be trained by Naruto himself to face threats that are beyond the capabilities of the regular ninja forces. It could explore how Naruto's leadership skills and his understanding of different ninja abilities would help in creating a formidable team.
You could write a fanfiction that delves deeper into the relationship between Arthur and Shinra. Maybe they get into a big argument over their different approaches to being a hero. Shinra believes in using his powers for the greater good in a more practical way, while Arthur is all about living out his 'knight in shining armor' fantasy. This argument could lead to them going their separate ways for a while, and then having to come back together to face a powerful Infernal that neither of them could defeat alone.
One idea could be to have the Rangers from Mystic Force and SPD team up to fight a common enemy that has the ability to manipulate both magic and advanced technology. This would create an interesting dynamic as the two teams have different skill sets.
One interesting idea could be a crossover with "Moana". Elsa's ice powers and Moana's connection to the ocean could create a really cool dynamic. Maybe Elsa accidentally freezes part of Moana's ocean and they have to work together to fix it. Another could be with "Tangled". Rapunzel's long hair and her adventurous spirit combined with Elsa and Anna's journey in Frozen 2 would be exciting. Rapunzel could use her hair to help them climb mountains or cross chasms. A third idea is a crossover with "Beauty and the Beast". Belle's love for books and knowledge could help Elsa understand more about her powers and the history of magic in the Frozen world.
One idea could be exploring an alternate universe where the Battle Force 5 team has different powers or vehicles. For example, instead of their regular rides, they could have flying saucers with unique offensive capabilities.