In a Rule 63 Qrow fanfiction, a great plot could be that she is the sole survivor of a major disaster that has befallen the Huntsmen community. She then has to rebuild and reform the community in her own image. This would involve her recruiting new members, training them in her own unorthodox style, and dealing with the political and social fallout of the disaster. She might also have to face her own inner demons and past mistakes during this process.
Well, a plot could involve gender - flipped Qrow being part of a traveling troupe of performers who also double as undercover agents for the good of Remnant. She uses her charisma and combat skills in a very different way than the original Qrow. Or perhaps she's trying to redeem a family name that has been tarnished in this Rule 63 world, facing many challenges along the way.
One plot idea could be a gender - swapped Qrow in an alternate universe where she is a mentor to a new group of young hunters. She could have different relationships with the other characters, like a more motherly bond with Ruby. Another idea is that she is on a mission to uncover a conspiracy within the Huntsman academies, using her unique skills and charm.
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 Qrow having to protect an endangered species all on his own. Maybe he discovers a unique Grimm - like creature that is on the verge of extinction and he has to fend off other threats while trying to understand it. Another could be that Qrow is part of a mission to save a group of people who are considered 'endangered species' in the RWBY world due to some new threat, and he has to use his skills and experience to lead them to safety.
One idea could be that Qrow discovers he's Weiss's father early on. He then tries to secretly protect her while also struggling with how to reveal the truth. Maybe he fears how Weiss will react given her family's reputation and her own relationship with her current family.
If Qrow was gender - swapped, her personality could have a different kind of charm. She might use her femininity in a way to manipulate situations to her advantage, but also be more empathetic. For example, she could be more patient when dealing with the younger characters, understanding their struggles on a deeper level. And instead of the gruff exterior the male Qrow has at times, she could have a more approachable and warm exterior while still being a tough fighter.
A more emotional fanfiction could be about Qrow trying to understand Raven's decision to leave. He could be on a journey of self - discovery as he tries to come to terms with his sister's actions. He might visit the places they used to go together, reminiscing about the good times and trying to figure out where it all went wrong.
A great plot twist could be that Raven is actually working undercover for a good cause all along, and Qrow discovers this in the middle of a fight against her. He thought she was a villain, but in reality, she was trying to stop a greater evil from within the enemy's ranks.
One interesting Uncle Qrow fanfic could be those that explore his relationship with Ruby. For example, a fanfic might focus on how he trains Ruby in secret combat techniques, adding more depth to their family bond.
Another interesting plot could be Qrow dealing with his own personal demons, like his alcoholism, while still being a father figure. He could struggle to set a good example for his child, but through the story, he gradually overcomes his issues. For example, his child might get into a dangerous situation because of his drinking habits, which serves as a wake - up call for him. And he then starts to change for the better to be a proper father.
Perhaps a fanfiction where Amber is revived in some unexpected way. Autumn, who might have some connection to the afterlife in the RWBY lore, helps bring her back. Qrow then has to deal with the implications of Amber's return and the potential chaos it could cause in the world of Remnant.
One idea could be exploring the backstories of the characters in more detail. For example, Jennifer's life before coming to the orphanage. Another could be creating an alternate ending where the girls form a more positive and healthy community instead of the dark one in the game.