A possible plot twist might be that the multiverse is starting to collapse and the RWBY characters have to find a way to stop it. They could discover that something they did in their own universe is what's causing the instability across the multiverse. So they have to go on a journey through different universes to correct their mistake and save not just their world, but all the worlds in the multiverse.
One cool plot twist could be that in one of the multiverse scenarios, their enemies are actually their allies. This would completely turn their understanding of good and evil on its head and force them to reevaluate their relationships. It could lead to some really intense character development as they try to figure out what this means for their own world.
A possible plot twist is that a character from RWBY gets influenced by a particular hero or villain from the WW2 documentaries. Let's say Ruby sees the courage of a WW2 soldier and tries to adapt that unwavering determination in her fight against the Grimm. Or perhaps a villain in RWBY is inspired by a dictator in WW2 and tries to take over their own world in a similar way. This could lead to a whole new set of conflicts and challenges for the RWBY team.
Well, they might see different versions of characters from Undertale. For example, the RWBY characters could be really surprised by the unique battle mechanics in Undertale's AU multiverse. Maybe Ruby would be especially interested in the different types of weapons or magic used in that world.
Blake could also be a great character to focus on. Given her own complex backstory and her tendency to be more introspective, she might have deeper insights into the characters and situations in the Undertale AUs. She could form unique relationships with some of the more morally ambiguous characters in the Undertale multiverse.
Another plot twist could be that Papyrus realizes the fight is all an illusion. In the fanfiction, he might see through some sort of magic or mind - control that was making Sans fight. So, he then has to figure out how to break the illusion and save Sans from this false battle.
One interesting plot twist could be when a character from Burgess who was thought to be just an ordinary person turns out to have a hidden power that is crucial in helping the Guardians. For example, a young girl might discover she can control ice like Jack Frost, which was unexpected and changes the whole dynamic of their fight against the bad guys.
There are several engaging plots in RWBY Watch Multiverse fanfiction. One is the idea of a multiverse - wide tournament where different versions of RWBY teams compete against each other. This allows for interesting character interactions and showcases different fighting styles. Another plot could be about a multiverse - breaking event that causes chaos and the main RWBY characters have to restore order. They might encounter versions of themselves that have turned evil due to the chaos. Additionally, a story where a character from a non - RWBY universe gets trapped in the RWBY multiverse and has to adapt and find a way home while also getting involved in RWBY - related adventures can be quite interesting.
A really interesting plot twist in 'Magic and RWBY: The Unexpected Alliance' is when the villains of RWBY team up with some of the darker forces in the Magic the Gathering universe. It makes the heroes reevaluate their strategies and forces them to find new allies among the Magic the Gathering characters.
One interesting plot twist could be that Soldier 76's time - traveling abilities (if we assume some extended lore) bring him to the RWBY universe during a crucial moment in a battle. His military tactics and advanced weaponry completely change the tide of the fight. Another could be that in the crossover, Soldier 76 has some sort of connection to one of the RWBY characters' pasts, like he was involved in an event that shaped their family history. And a third plot twist might be that his healing abilities become a key factor in saving a major RWBY character from a near - fatal injury, leading to a new alliance between him and the RWBY team.
Ruby herself could have major revelations. Since she's the main character, seeing different versions of herself and different ways her story could have gone might make her question her own path and purpose.
The fanfic could start with some of the RWBY characters being summoned to the Avengers' world. Iron Man, being the curious and innovative one, is immediately intrigued by their weapons and Semblances. The Avengers then learn about the Grimm and the threats in the RWBY multiverse. They decide to travel there with the RWBY characters. Once in the RWBY multiverse, they face challenges like dealing with Salem's forces and also trying not to disrupt the balance of this new world while still helping to fight the evil.