What are some interesting ideas for 'rwby penny crossover fanfiction'?

One interesting idea could be a crossover of different timelines within RWBY. For example, characters from the past meet the current ones and have to deal with the differences in their worlds. Another could be a crossover of different teams in unexpected ways, like Team RWBY having to team up with a rival team to face a common enemy that is more powerful than any they've faced before. And sometimes, there are crossovers that involve alternate versions of the characters, where their personalities or abilities are slightly different, which can lead to very unique and engaging storylines.

Maybe the OC has a special power that only Penny can understand or help control. For example, if the OC can manipulate time in small bursts, Penny's robotic nature might be able to analyze it and they could use this power to save the day during a Grimm attack.

One idea could be that Superman arrives in the RWBY world and has to learn about Dust and its powers. He could team up with Team RWBY to fight a common enemy, like a powerful Grimm that is immune to normal attacks but not to Superman's strength. Another idea is that Ruby discovers she has some Kryptonian-like abilities and Superman helps her understand and control them.

One idea could be the Doom Slayer arriving in the RWBY world. He could be on a mission to stop some sort of demonic invasion that has seeped into Remnant. His powerful arsenal and unwavering determination would be a huge contrast to the Huntsmen and Huntresses of RWBY.

Another interesting concept is that some of the Titans could be modeled after the RWBY characters' weapons or fighting styles. For instance, a Titan with a scythe - like weapon similar to Ruby's Crescent Rose, and it could have a special ability based on her speed and agility.

One idea could be that Saitama from OPM ends up in the RWBY world and participates in a Grimm - slaying tournament. His overwhelming strength would shock everyone, and he might just be in it for the free food at the event.

For 'rwby multi crossover fanfiction', a crossover with 'Fullmetal Alchemist' would be interesting. RWBY characters could interact with the alchemists and learn about alchemy. They might even find ways to combine their Semblances with alchemy. Also, a crossover with 'My Hero Academia' would be exciting. The RWBY heroes could train with the students at U.A. High and exchange combat techniques and strategies.

Another interesting aspect could be a story where the Grimm from RWBY are somehow affected by the technology of the MMZ world. Maybe the Maverick virus gets mixed up with the Grimm essence, creating new and more dangerous hybrids. The characters would then have to figure out how to stop these hybrids while also dealing with the cultural differences between their two worlds.

One idea could be to cross your original character (OC) with the world of RWBY and have them be a transfer student at Beacon Academy. They could bring unique skills or powers from their own world, like a magic system that RWBY doesn't have. Another idea is to have the OC be from a different time period and get thrown into the RWBY universe, causing all sorts of chaos and new storylines. For example, an OC from a steampunk world with advanced machinery could introduce new tech to the RWBY characters.

One idea could be that the characters from RWBY end up in the Fallout wasteland. Ruby could use her scythe skills to fight off raiders and mutants. Weiss might use her glyphs to protect the group from radiation in certain areas. Another idea is that the Dust from RWBY could be a valuable resource in the Fallout world, leading to various power struggles.