One possible interesting plot could be that the Survey Corps discovers a titan that has some sort of connection to the Kaiju from Pacific Rim. Maybe the titan has a similar biology or origin. They could then team up with the Jaeger pilots to study it and figure out how to defeat both the titans and the Kaiju. The Jaeger pilots could teach the Survey Corps about their advanced technology, while the Survey Corps shares their knowledge of fighting in a more primitive, yet effective way against the huge and dangerous enemies.
In this crossover fanfiction, there could be a situation where a powerful Kaiju has some sort of ability that is affecting Godzilla's normal behavior. The Pacific Rim team has to figure out how to reverse this effect while also fighting off other Kaiju threats. They send in their most advanced Jaeger to try and communicate with Godzilla and form an alliance. Along the way, the pilots of the Jaeger learn about Godzilla's history and the ancient battles it has fought against similar threats.
Eren and Raleigh would be likely to team up. Eren has his powerful titan - shifting abilities which could be useful in close - combat situations against both titans and Kaiju. Raleigh, with his experience in piloting a Jaeger, could guide Eren on how to better use his powers in coordination with the large - scale technology of the Jaegers. They could form a strong bond as they both have a strong sense of justice and a desire to protect their respective worlds.
One possible plot could be that the Avengers are somehow transported to the world of Attack on Titan. They team up with the Survey Corps to fight the Titans. Iron Man could use his high - tech suits to take on the Titans from a distance, while Captain America leads the ground troops along with Eren and his friends. Thor could use his lightning powers to stun the Titans, making it easier for the others to attack.
One possible plot could be that Naruto and his friends are transported to the world of Attack on Titan. Naruto's ability to use chakra and his ninja skills could be used to fight the Titans in a unique way. For example, he could use his Shadow Clone Jutsu to create multiple clones to distract the Titans while the Survey Corps tries to attack their weak points. His Rasengan could also be a powerful weapon against the Titans' tough skin.
One possible plot could be that the Titans are actually some kind of ancient, corrupted Transformers. The Survey Corps discovers a hidden technology that has the power to control or at least influence the Titans. Eren, with his Titan - shifting ability, might have a special connection to this technology. The Autobots arrive on the scene, initially seen as a threat by the humans. But as they learn about the Titans, they team up with the Survey Corps to fight against this common enemy, using their advanced weaponry and Eren's unique power.
One idea could be that the Jaegers are equipped with Transformer technology. For example, their power cores could be replaced with energon, giving them new abilities. Another plot could involve the Transformers teaming up with the Jaeger pilots to fight a common enemy that threatens both Earth and Cybertron. Maybe a new breed of Kaiju that can also assimilate Transformer technology.
A crossover with the Godzilla universe. Maybe the Jaegers are called in to assist when Godzilla is facing an especially powerful and numerous Kaiju horde. The Jaegers' advanced weaponry and strategic capabilities could complement Godzilla's raw power in this scenario.
One possible plot could be that Naruto and his friends discover a portal that leads to the world of Pacific Rim. There, they learn about the Kaiju and the Jaegers. Naruto, with his chakra powers, could potentially be a great asset in piloting a Jaeger. He might even develop a new form of combat style that combines his ninja techniques with the technology of the Jaegers.
In this crossover fanfiction, the pilots of the Jaegers could be sent to Godzilla's world to learn from his survival skills. Godzilla has been around for a long time and has survived many battles. The pilots observe how Godzilla uses his environment, his strength, and his atomic breath. They then take this knowledge back to their world and use it to upgrade their Jaegers' combat strategies. For example, they might learn new ways to dodge attacks or use the terrain to their advantage like Godzilla does.
One idea could be a crossover with the Transformers universe. Picture Jaegers and Transformers teaming up to fight a common enemy. Another could be a crossover with the Godzilla franchise, where the Jaegers have to deal with Godzilla while also facing their usual Kaiju threats. A third idea might be a crossover with the Star Wars universe, perhaps with Jaegers having some sort of technology exchange with the droids or the Jedi using their powers in the context of the Pacific Rim battles.