A possible crossover could involve the magic system of Harry Potter being combined with the Gem technology in Steven Universe. For example, Hermione could study how the Gems' powers work and try to find a scientific explanation for it. On the other hand, Pearl could be fascinated by the complex spells in the wizarding world. And perhaps Dumbledore and Garnet could have a deep conversation about leadership and protecting their respective worlds.
I think Harry and Steven would be the most interesting. Harry has his own burdens of being the 'Chosen One' in the wizarding world, and Steven has to deal with his role as a half - Gem. They could understand each other's struggles and learn from each other's ways of handling difficult situations.
One interesting crossover could be the use of magic in the Steven Universe world. For example, Steven might learn some basic spells from the Harry Potter universe and use them in his own world to solve problems in a new way. Maybe he could use a levitation spell to move the big rocks around on the beach more easily.
Peridot is quite popular too. Her unique personality, especially her growth from a somewhat antagonist to a more friendly character, makes for great storytelling in crossovers. In a crossover with 'Ben 10', Peridot's technological knowledge could be paired with Ben's Omnitrix - related adventures.
Well, it could be really cool. Maybe the Gems would be intrigued by the technology of the Omnitrix. Steven might try to understand Ben's powers better and see if there are similarities between his gem powers and Ben's alien forms. And Ben could learn about the Gem culture. They could also exchange stories about their adventures and how they protect their respective universes.
To write a good Steven Universe FNAF crossover fanfiction, you need to consider the tone. Since Steven Universe is more light - hearted in general and FNAF is horror - based, find a balance. You could start with the Steven Universe characters in their normal setting and then gradually introduce the FNAF elements. Let the characters react realistically to the new and scary situation. For instance, Amethyst might initially be curious about the animatronics but then get scared when they start acting strangely.
It could be really interesting. Maybe the gems from Steven Universe end up in the spooky world of FNAF. They could use their powers to fight off the animatronics. For example, Garnet's strength could be used to hold the animatronics back while Pearl uses her spear to disable them.
Well, in such a crossover, Steven could use his gem powers to help the Avengers in battles. Maybe his healing powers could be used on the injured Avengers. For example, after a tough fight with a powerful villain like Thanos, Steven could heal Captain America's wounds.
First, know the characters well from both universes. For Steven Universe, understand the powers and personalities of the Crystal Gems and Steven. For Transformers, know the Autobots and Decepticons. Then, find a good starting point for the crossover, like an unexpected encounter. Don't forget to keep the tone consistent with both franchises.
It could be really cool. Imagine Steven's gem powers interacting with the Transformers' technology. Maybe the Crystal Gems could help the Autobots in some way, like using their powers to repair damaged parts. Or the Transformers could introduce new ways of using energy to the Gems.