They could be mentors. Since they possess different combat skills like ninjutsu, they could teach RWBY characters new ways of fighting. For example, teaching Ruby how to move faster using Naruto - style movement techniques.
Perhaps in the fanfiction, the White Fang could be reimagined as a group with a similar ideology to the White Fang in RWBY. They could be fighting for the rights of some marginalized group in the RWBY world, using their Naruto - inspired skills. For instance, they might use chakra - based attacks, which would be a completely new concept in RWBY. This could lead to interesting interactions between the RWBY characters and the Naruto - inspired White Fang as they try to understand and either oppose or support this new group.
First, Naruto would address the root of the White Fang's bad reputation. If there were past misdeeds, he'd make amends for them in a proper way. He'd lead the White Fang in acts of selfless service, like providing food and shelter to refugees. He'd also share the stories of the White Fang's new beginnings and their efforts to be better. This would slowly but surely change how people view the White Fang. He might even organize events where the White Fang could show their skills in a non - threatening way, like a friendly ninja competition, to gain the public's trust.
Naruto could be a mentor - like figure. His experience with different types of combat and his rinnegan - enhanced perception would allow him to guide the RWBY characters in battles. He might help Ruby improve her scythe - wielding skills by teaching her some of his sword - fighting techniques that he learned from Sasuke.
A Naruto mercenary in a RWBY fanfiction could be a wild card. They might be a hired gun for the bad guys, causing trouble for the RWBY team. Or they could be a lone wolf who ends up helping the heroes when it suits their own goals. Their role could also be that of a teacher, sharing Naruto - style combat knowledge with the RWBY characters.
A SPAS - 12 could play the role of a powerful and unexpected weapon in RWBY fanfiction. If a character gets hold of it, it could give them an edge in combat against Grimm or other enemies. It might also attract unwanted attention, like from the authorities in the RWBY world if it's an illegal or unregulated weapon there.
Often, it plays a strategic role in combat. It gives Blake an edge in battles, allowing her to outmaneuver her foes.
An OC that is a spy within the White Fang for a different organization. They are trying to figure out the White Fang's true intentions and stop any potential terrorist activities. This would involve a lot of secrecy, betrayal, and moral dilemmas as the OC gets closer to the truth.
It could be Adam Taurus. He's a well - known and very radical member of the White Fang in the RWBY universe. His extreme views and violent methods would put him directly at odds with Ruby's more peaceful and inclusive approach.
One reason could be a change in his ideology. Maybe he realizes the extreme methods of the White Fang are not the right way to achieve equality for the Faunus. He might have seen how the violent actions are only causing more harm than good.
The white snake might be a symbol of a long - lost prophecy. In the fanfic, there could be an ancient prophecy that speaks of a white snake appearing when the world is in great danger. The characters then have to figure out what the snake's purpose is and how it relates to the impending doom. This could involve a lot of research into old scrolls and talking to wise elders in the Naruto villages.