Maybe the RWBY characters end up in the world of Ghost Recon. They would be in a completely different environment, with no Grimm but new threats like human enemies. The RWBY characters would have to adapt their fighting styles. Ruby, with her speed, could be used for quick reconnaissance missions, while Weiss could use her Glyphs in creative ways to assist the Ghost Recon team in combat situations.
Another plot could involve a joint mission where the Ghost Recon team and RWBY characters are after a powerful and mysterious artifact. The Ghost Recon members are after it for its potential military applications in their world, while the RWBY characters want to keep it safe from falling into the wrong hands in their world. They have to learn to work together, despite their different backgrounds and fighting methods.
Another concept could be the team - building aspect. Characters from RWBY and Ghost Recon could form mixed teams. They would have to learn to work together, with the RWBY characters bringing their individual skills and the Ghost Recon operatives their military training. This could create some interesting character dynamics, like Yang's brashness contrasting with the more methodical approach of a Ghost Recon soldier.
One idea could be an OC who is a former criminal turned informant for the Ghosts. They have unique skills from their past life that help the team in unexpected ways. For example, they know all the secret passages in the drug cartel's strongholds because they used to work with some of the lower - level members.
One idea could be a crossover with another military - themed game like Call of Duty. The Ghosts could team up with the COD characters to take on a global terrorist threat that neither could handle alone. They would have to combine their unique skills and weaponry.
One idea could be to create a story where the Ghosts have to operate in a completely urban environment instead of the usual wilderness. They could face new types of enemies like organized crime syndicates with high - tech gadgets. Another idea is to write a fanfic about a Ghost who gets separated from the team and has to survive on their own while being hunted by the enemy. It would add an element of survival and isolation to the story.
One idea could be that Sam Fisher from Splinter Cell has to team up with a Ghost Recon squad to infiltrate a highly guarded terrorist base in the mountains. They combine Sam's stealth skills with the Ghost Recon team's military tactics and advanced weaponry.
Another plot could involve a RWBY character ending up in the Naruto universe. Say, Weiss gets sent to Konoha. She might initially struggle with the different culture and the use of chakra, but eventually she could use her Glyphs in unique ways by combining them with chakra. This could also lead to some interesting interactions between her and the ninja students there.
A cool plot could involve the characters from Frozen getting stuck in the RWBY world and having to learn how to fight Grimm. Anna might be really eager to learn combat skills, while Elsa is more focused on controlling her powers in this new and dangerous environment.
One idea could be that Gilgamesh, with his vast power and arrogance, arrives in the RWBY world. He might initially see the Huntsmen and Huntresses as beneath him but then becomes intrigued by Ruby's unique silver - eyed power. Another could be a scenario where Gilgamesh allies with a villain in RWBY, like Cinder, and together they try to reshape Remnant according to their desires.
One idea could be to cross it with a cyberpunk world. The Ghost Recon team has to navigate a high - tech, dystopian city filled with neon lights and hackers. They could be after a rogue AI that has ties to a powerful criminal syndicate. Another idea is a crossover with a post - apocalyptic setting. The soldiers find themselves in a world ravaged by war and must use their skills to survive and protect the remaining survivors from raiders.
One plot idea could be Ruby trying to redeem Torchwick. Since he's a villain in the original series, Ruby could see some good in him and attempt to turn him to the side of good. This would involve a lot of character development for both of them as they interact and Ruby tries to break through Torchwick's tough exterior.