Perhaps the Nameless King has lost his memory upon arriving in RWBY's world. He wanders around, confused, and is found by Ruby. Ruby, being the kind - hearted leader, decides to help him. As he regains his memories bit by bit, he discovers a connection between his past and a hidden power in Remnant that could change the fate of both worlds.
A possible plot could involve the Nameless King being a key figure in an old prophecy in the RWBY universe. Some people believe he will bring destruction, while others think he is the savior. Team RWBY has to figure out which side he is really on and whether they should trust him or not. This leads to a series of adventures and battles where they gradually learn more about his true nature.
One idea could be the King of Vacuo having to deal with a new, powerful Grimm threat that RWBY and their friends must help him face. Maybe he has a hidden past related to an ancient Vacuoan magic that could turn the tide against the Grimm.
One plot idea could be that Ruby discovers a hidden connection between her Silver - eyed powers and Ozma's ancient magic. Maybe she has visions that lead her to an old relic related to Ozma. Another could be that they team up to fight a new, powerful Grimm threat that is immune to normal Huntsman attacks, but Ruby's unique abilities combined with Ozma's knowledge can defeat it.
A plot idea could be that a new, mysterious game appears in their world. The game seems to have a mind of its own and starts to manipulate the players. RWBY has to figure out the rules of the game and how to break free from its control. Along the way, they meet other characters from their world who are also trapped in the game, and they all have to work together. This would create a lot of action - packed scenes as well as opportunities for character growth and interaction.
One idea could be that Blake and Yang have a very emotional first encounter during the reunion. Maybe Blake has been through a lot on her own journey and when she sees Yang, she just breaks down in tears. Yang, on the other hand, is initially a bit hesitant but then just hugs Blake tightly. Another plot could involve them having to face an immediate threat together right after the reunion, which forces them to quickly fall back into their old teamwork rhythm. And perhaps during this time, they start to realize that their feelings for each other have grown even deeper.
A plot could involve a mysterious figure from another dimension arriving in the RWBY universe with Ultra Instinct abilities. This figure could either be an ally or an enemy. If an ally, they could teach the RWBY characters how to access this power. If an enemy, the RWBY team would have to figure out how to counter this seemingly invincible ability. Also, perhaps there could be a side - story where a non - combatant character in RWBY, like a mechanic or a strategist, plays a crucial role in helping a fighter understand and use Ultra Instinct.
One plot idea could be Ruby and Winter teaming up for a special mission. Maybe they have to infiltrate an enemy stronghold. Ruby's speed and Crescent Rose could be combined with Winter's ice powers and combat skills for some epic fight scenes.
One plot idea could be exploring their past relationship at Beacon Academy. Maybe they had a mission together long ago that went wrong and it's now affecting their current dynamic. Another could be a story where they have to face a powerful enemy together and in the process, they rediscover their trust in each other. A third idea might be a story set in an alternate universe where Ozpin and Glynda are not teachers but adventurers on a quest for a powerful relic.
One plot idea could be Qrow training Ruby in some special combat techniques that are unique to his own fighting style. This would allow Ruby to gain new skills and also strengthen their bond as family members.
One idea could be Ruby trying to understand Salem's motives beyond just destruction. Maybe she discovers that Salem has a tragic past that led her to this path and Ruby attempts to find a way to redeem her. Another plot could involve Salem targeting Ruby specifically because of her silver - eyed powers and Ruby having to outwit Salem in a series of battles.
A possible plot for a fanfiction about Whitley and Ruby in RWBY could be that they are both chosen for a special task by Ozpin (or his successor). They are the least likely pair to be chosen together, but as they work on the task, they find out that they complement each other well. Whitley's knowledge of Atlas society and technology, combined with Ruby's combat skills and leadership, make them a formidable team. Along the way, they might face challenges from within the group that doesn't believe in their partnership, but they prove everyone wrong by achieving their goals successfully.