It would disrupt the traditional view of Grimm as villains. Huntsmen and Huntresses would have to find new ways to interact with them. Instead of just fighting, they might need to communicate. For instance, Blake could try to understand the language or signals of friendly Grimm to work together against other threats.
A RWBY fanfic with friendly Grimm could also introduce a new type of conflict. There might be those in the RWBY world who oppose the idea of friendly Grimm and see them as still a threat. This could lead to internal strife among the characters, with some believing in the potential of the friendly Grimm and others trying to eliminate them.
The plot could shift towards exploring the reasons for the Grimm's friendliness. Is it a mutation? Or is there some external force at work? Teams RWBY and JNPR might split up to investigate different aspects of this phenomenon. This would create multiple sub - plots and expand the overall scope of the story.
One possibility is that friendly Grimm could completely change the dynamic of the RWBY world. Instead of being pure threats, they might become allies or at least neutral entities. This could lead to new storylines where characters have to re - evaluate their understanding of the Grimm. For example, Ruby might be initially hesitant to trust a friendly Grimm but then realizes it can help in a certain situation.
Sentient Grimm might also form alliances with certain characters or groups. This would completely shift the power balance in the story. Maybe a group of villains in RWBY would team up with the sentient Grimm to achieve their own goals, leading to a much more complex and unpredictable plot. They could also be a source of new information, like knowledge about ancient Grimm secrets or powers that no one else knew about, which could also drive the plot forward in new directions.
Magic could be one way. In the RWBY universe, there could be some form of ancient magic that can change the nature of a Grimm. A character might discover a spell or a magical artifact that has the power to make a Grimm friendly. They would then have to figure out how to use it properly without any negative side effects.
First, focus on the positive aspects of the RWBY world like the friendship and loyalty among the characters. When writing about the Grimm, describe them in a way that is spooky but not overly gory or disturbing. For example, you can say that the Grimm are shadowy figures that lurk in the darkness rather than going into graphic details of their appearance. Also, keep the plot centered around themes like courage, determination, and hope.
First, you need to establish Velvet's character traits clearly. Since she is often underestimated, you could use that as a starting point. For instance, in the face of a Grimm attack, others might not expect much from her, but she surprises them with her resourcefulness. Then, introduce an interesting Grimm. Maybe it has some unusual powers or a strange origin. The conflict between Velvet and this Grimm can drive the plot. For example, if the Grimm can mimic the appearance of humans, it creates a lot of confusion and danger.
One idea could be a story where Velvet discovers a new type of Grimm with unique abilities. She then has to figure out how to combat it, using her skills and the help of her friends. Maybe she could study the Grimm's behavior and weaknesses in secret to surprise everyone when she reveals her knowledge.
One plot idea could be a group of hunters discovers a new type of Demonic Grimm that can possess other Grimm, creating an army. They have to find the source of this new threat and stop it before it overcomes all of Remnant. Another could be a young huntress in training who has a special ability to sense Demonic Grimm and she teams up with some unlikely allies to face a powerful Demonic Grimm lord that has been hidden for centuries. A third idea is that the Demonic Grimm start to corrupt the minds of some of the hunters, turning them against their own kind, and the remaining hunters have to fight both the Demonic Grimm and their former comrades.
One idea could be Ruby facing a new type of Grimm that has unique abilities, like the ability to manipulate time in a small area. This would put Ruby in a tough situation where she has to figure out how to combat it while being affected by the time distortion. Another plot could involve Ruby getting lost in a Grimm - infested area and having to rely on her wits and the little resources she has to survive and find her way back to her team.
One idea could be that the characters have to face a new type of Grimm that has emerged from the Pacific region. These Grimm could have unique abilities like being able to camouflage in the ocean or use water-based attacks. Another plot could involve the team having to form an alliance with a local group in the Pacific area who have their own ways of dealing with Grimm.
In some 'rwby friendly grimm fanfiction', a Grimm could be charmed by a RWBY character's semblance. Let's say Ruby's speed semblance is so fascinating to a Grimm that it decides to follow her around instead of attacking. This could lead to a story where Ruby has to deal with having a Grimm as a sort of 'pet' or follower, and how the other characters react to this strange situation.