Well, a plot could be centered around an ancient tech that was hidden away because it was too powerful. The characters accidentally stumble upon it. For example, it could be a technology that can open portals to other dimensions. They then have to deal with the consequences of opening these portals, like new and dangerous enemies coming through. Also, the fanfic could explore how this ancient technology was created in the first place. Was it made by the same people who created the Dust? Or was it from an even more ancient civilization?
One idea could be exploring the lost technologies of the ancient kingdom. Maybe the characters discover a hidden vault filled with advanced weapons or energy sources that were used in the past. Another could be delving into the political structure of the ancient kingdom, like if there were different factions or noble houses that vied for power.
Some concepts might involve the relationship between the ancient technology and the Dust in RWBY. Maybe the ancient technology was designed to work with Dust in a more efficient way. Or perhaps it has the power to control or manipulate Dust in ways that are currently unknown. This could lead to new plot developments and power struggles within the RWBY universe.
One idea could be a choice where the characters have to decide whether to ally with a mysterious new group in Vale. This new group seems to have some unique powers and resources, but their motives are unclear. It could lead to different story arcs depending on the choice made.
One idea could be a character getting a tattoo that has a hidden power. For example, a RWBY character might get a tattoo that glows when danger is near, like a warning sign. Another plot idea could be a story centered around a tattoo artist in the RWBY universe who creates unique tattoos for the Huntsmen and Huntresses, and each tattoo gives them a special ability or connection to the Dust energy. Maybe a tattoo that allows a character to communicate with Grimm in a strange way, adding an interesting twist to the story.
One idea could be a story where the characters from RWBY have to face a new, extremely powerful Grimm that has unique abilities. This Grimm could be immune to certain types of Dust, forcing the team to come up with creative combat strategies. Another plot could involve a tournament within the RWBY battlefield, where different teams compete not just for victory, but also for a rare and powerful relic. This would add an element of competition and strategy among the characters.
Perhaps Sasuke is mistaken for an enemy at first. His strange powers and appearance raise suspicion. But as the story progresses, it's discovered that he has knowledge of a greater threat that is coming to the RWBY world, something that might be related to his own past experiences. So he teams up with the RWBY characters to prepare for this threat.
One idea could be the RWBY characters teaming up with the Payday gang to steal some valuable Dust from a powerful and corrupt company. They'd have to use their unique skills, like Ruby's speed and Crescent Rose, combined with the Payday crew's heist expertise.
One idea could be the young RWBY characters having a mini adventure in the woods near their homes. They might discover a strange creature and try to befriend it. Another could be them having a pretend battle tournament in their backyard, with each using their unique abilities in a more innocent and unrefined way.
One idea could be exploring new Grimm species in the RWBY GP fanfic world. Maybe there are Grimm that can blend into the environment in a more advanced way, like turning into man - made structures to ambush Huntsmen and Huntresses. Another plot could revolve around a new character who has a unique weapon design that combines different Dust types in an unorthodox way, and they have to prove themselves in the academy.
One idea could be that a Forerunner technology is discovered in Remnant. The characters in RWBY then have to figure out how to use or protect it from the villains. Maybe it's a powerful weapon that could change the balance of power in the world.