In this fanfiction, perhaps Kakashi and Tobi meet in a battle. Kakashi might initially be suspicious of Tobi's true identity. Tobi could be playing mind games with Kakashi, trying to throw him off his game.
Kakashi could become more distrustful after meeting Tobi. Since Tobi is such a mysterious figure, Kakashi might start to suspect everyone around him more.
One possible plot could be that Tobi, Sakura, and the female reader all end up on a mission together. Tobi's unpredictable nature might create some comical situations at first. Sakura, with her medical and combat skills, would be a reliable ally. And the female reader could have some unique abilities that help them overcome the challenges in the mission, like perhaps the ability to communicate with animals which gives them an edge in a forest - type mission.
Perhaps an organization that is trying to steal Sakura's medical knowledge for their own evil purposes. They view Tobi as a threat because of his combat skills and the fem reader as a potential source of information about Sakura. So they send their agents to target all three of them.
A 'sasuke meets oc fanfiction' could be really interesting. It might explore new relationships and character developments. Usually, when Sasuke meets an original character (oc), it can lead to various plot twists. For example, the oc could be from a different ninja clan with unique abilities that Sasuke has never seen before. This could either make them allies or enemies depending on the circumstances. The fanfiction could also delve into Sasuke's reaction to this new character, whether he is suspicious, intrigued, or dismissive at first.
Sure. One great 'tobi meets fem reader fanfiction' might be 'Tobi's Encounter' which has a really interesting plot where Tobi and the female reader meet in a mysterious forest setting. It's full of adventure and some sweet moments.
Sasuke might be initially surprised. He is used to the Sakura from his past, so seeing a different, more mature future Sakura could catch him off guard.
Sasuke would likely be aloof and guarded at first. He might see Batman as just another 'vigilante' like some of the shinobi in his world. Batman, on the other hand, would be cautious and try to figure out Sasuke's motives. Eventually, they could start sharing their combat techniques. Sasuke might show Batman how to use chakra in combat, and Batman could teach Sasuke about the importance of having a strong moral code.
In a Sarada meets past Sasuke fanfiction, it could be that Sarada has to keep her identity a secret at first. She might be on a mission in the past for some reason. As she observes past Sasuke, she could notice his skills and the way he interacts with others, like Naruto. This would give her a chance to understand the bond between her father and Naruto from a whole new perspective, which could be really interesting for the readers.