Well, a Saiyuki crossover fanfiction could involve crossing it with a post - apocalyptic world. The Saiyuki gang would have to adapt to the harsh new environment, deal with new threats like mutated creatures and fight for survival. Or perhaps a crossover with a space - opera setting. They could travel among the stars, encounter alien species and get involved in intergalactic politics.
A great Saiyuki crossover fanfiction idea could be to cross it with a historical setting. For example, the characters could be thrown into the feudal era of Japan. They would have to navigate the complex social hierarchies, deal with samurai and shoguns. This would bring a whole new dynamic to their relationships and adventures. They might also introduce new elements from their own world into this historical context, which could lead to some really interesting plot twists.
One idea could be exploring a time when Sanzo loses his memory and Goku has to help him remember who he is and their mission. This would create a lot of emotional moments as Goku tries to jog Sanzo's memory with their shared experiences.
One interesting Saiyuki fanfiction could be a story that focuses on the backstories of the characters before they set out on their journey. For example, it might explore Sanzo's training in more detail, showing how he developed his tough exterior and his relationship with his master. Another could be a fanfiction where the group encounters a new and powerful demon that challenges their beliefs and teamwork in ways they haven't experienced before. And there are also fanfictions that might explore romantic relationships between the characters in a way that adds a new layer to their dynamics.
There could be a Saiyuki OC fanfiction where the OC is a time - traveler. They accidentally end up in the Saiyuki world and have to find a way back home. Along the way, they interact with the main characters and learn about their destinies, and might even change some small events in the story for the better.
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.
Honestly, all of the main characters in Saiyuki have their own unique qualities that make them great for crossovers. Goku's growth throughout the series can be an interesting arc to explore in a crossover. Sanzo's role as a protector can be emphasized in different settings. Gojyo's backstory can be expanded upon when combined with new worlds. And Hakkai's mysterious past can be delved into further in a crossover, making any of them a worthy focus.
A Rambo crossover fanfiction could involve him crossing over into the Star Wars universe. Rambo's guerilla warfare tactics could be interesting in a galaxy far, far away. Maybe he helps the Rebel Alliance in a ground - based battle against the Empire. Or a crossover with the Predator series. Rambo would be a worthy opponent for the Predator, and the fight between them in the jungle could be epic. Also, a Rambo and John Wick crossover would be intense, two highly skilled fighters on the same side or perhaps initially at odds.
One idea could be a crossover with a modern military setting. The Decepticons could be trying to steal advanced military technology. Another is a crossover with a post - apocalyptic world where they are competing with other factions for resources. A third could be a crossover with a magical realm, with the Decepticons trying to harness the magic for their own evil purposes.
One idea could be a crossover with Naruto. Kakuzu could be sent to the Naruto universe and form an unlikely alliance with a shinobi village to fight a common enemy, like the Akatsuki from his own world turned rogue in the new universe. This would create a lot of interesting character dynamics and battles.
Another option is a crossover with 'The Little Mermaid'. The characters from the descendants could meet Ariel and her friends underwater. Evie might be interested in the mermaid fashion and could design new outfits inspired by the underwater world.
Another possibility is a crossover with the world of Naruto. The characters from MHA could participate in the Chunin Exams. Bakugo might be really into showing off his skills in this new and different kind of competition.