Who could be the main antagonist in 'ruby rose meets team slvr fanfiction'?

Well, it could be about Ruby Rose joining forces with Team SLVR in a battle against a common enemy. Maybe they initially have some misunderstandings due to their different ways of doing things, but gradually learn to work together and become a strong team.

The main characters are likely the members of Team SLVR themselves. Each member would have their own unique abilities, personalities, and backstories that contribute to the story.

It could be a rogue ninja from a rival village. This ninja has a personal vendetta against Konoha and specifically targets Team 10 because of Naruto's presence. He might be jealous of Naruto's growing power and fame and wants to prove himself by defeating the team.

It could be Salem. She has always been interested in the power of the silver eyes, and Ruby having those eyes makes her a prime target. Salem might send her minions to kidnap Ruby, which would lead to her disappearance.

It could be a powerful vampire coven. They might see Buffy and the wet works team as a threat to their plans of taking over the city or a particular area. The vampires could use their powers of seduction and mind control to try and turn the wet works team against Buffy or vice versa.

Perhaps an old enemy of one of the members of Team 9 shows up. Since Naruto has joined the team, they might see it as an opportunity to get revenge. This antagonist could be someone who was once defeated by the member's family and now wants to prove themselves. They would be very cunning and use their knowledge of the team member's past to try and divide the team.

It could be Danzo. He's always been a bit of a shadowy figure in the Naruto series. Maybe he sees Naruto as a threat to his power and influence in the village and manipulates the situation so that Team 7 has to abandon him. He would be a great main antagonist as he has the resources and the motives to cause such a rift in Team 7.

It could be Orochimaru. He might see the baby versions of Team 7 as perfect subjects for his experiments. He could try to kidnap them to use their unique chakra or potential for his own dark purposes.

Perhaps an ancient evil spirit that was sealed away long ago in Naruto's world but gets awakened by Ruby Lemon's presence. This spirit has the ability to possess people and use their skills for its own ends. It starts to cause chaos in the ninja villages and targets Ruby Lemon and Naruto specifically, seeing them as the key to either its complete destruction or its total domination.

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.