One idea could be exploring the backstory of how the Silent Knight came to be. Maybe he was once an ordinary Huntsman who faced a great tragedy that led him to his silent and brooding state.
One interesting plotline could be the development of the relationship between the main characters in a unique way that differs from the original RWBY series. For example, they might face new challenges together that force them to rely on each other more, deepening their bond.
Another plot could involve Weiss using her family's resources to create technology similar to what's in Arkham Knight's world to combat a new type of Grimm. And the Arkham Knight himself might be interested in this tech and try to steal it, leading to an interesting conflict and alliance between Weiss and the other RWBY characters against him.
It could be a powerful and corrupted Huntsman. He might have once been a colleague of the Silent Knight but was consumed by greed for power. He now uses his skills to create chaos and try to take over the kingdoms, and the Silent Knight has to stop him.
A cool Silent Hill fanfiction idea is to focus on the psychological aspect more deeply. Maybe write about a psychologist who visits Silent Hill to study the mental states of the people there. He gets trapped and starts to experience hallucinations related to his own past traumas. Also, a fanfiction where the monsters in Silent Hill are given a chance at redemption. What if they could be cured of their 'evil'? It would be an interesting take on the usual horror theme.
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.
Some fanfictions might focus on the relationships the Remnant Knight has within the RWBY universe. For example, how they interact with Team RWBY. They could be a mentor figure, teaching the team about ancient Remnant lore and combat techniques that are unique to the Remnant Knight's heritage.
One interesting plot could be a Knight character who was once on the wrong side, but through interactions with the RWBY team, begins to see the error of their ways and strives for redemption. They might have to face old allies who are still on the dark path and fight against them to prove their new allegiance.
Well, it likely includes characters from RWBY like Ruby, Weiss, Blake, and Yang. But in the context of the Silent Knight fanfic, there might be a new character who is the Silent Knight. This character could be a mysterious figure with unique abilities and a backstory that ties into the RWBY universe in some way.
You could write about an oc who is a survivor from a previous encounter in Silent Hill but has to return for some reason. Maybe they left something behind that is important to them and they face new terrors on their return journey.
One interesting idea could be the development of new and unique jutsu related to silent killing. For example, a character might create a jutsu that allows them to move completely silently while also enhancing their attack power. Another idea could be the exploration of how different characters in the Naruto universe adapt to this style of combat. Some might struggle with the stealth aspect, while others might thrive.