Kakashi could become more distrustful after meeting Tobi. Since Tobi is such a mysterious figure, Kakashi might start to suspect everyone around him more.
For Konan, her relationship with paper and her use of paper - based jutsu is a big part of her character. Writers should incorporate this into the story in a meaningful way. For example, if she is in a fight or a tense situation, her paper abilities should be used in a way that is consistent with how she uses them in the anime/manga. Tobi's use of his unique abilities like intangibility and teleportation should also be written in a way that makes sense for his character. His way of speaking, which is often a bit cryptic, should also be maintained in the fanfiction to keep him in - character.
Well, in this fanfiction, it could be that Harry Potter has come across some sort of ancient magic or artifact that has changed him. Maybe this magic has a connection to Tobi's essence or the type of power that Tobi wields. Additionally, he might be trying to protect his friends in a different way. Tobi has his own way of safeguarding what he holds dear, which might seem appealing to Harry in a difficult situation. Or, there could be a prophecy or a hidden message that he has misinterpreted, leading him to believe that acting like Tobi is the right path to take.
Well, there is some. However, the quality can vary greatly. Some might focus more on the emotional side of their relationship, while others could be more action - packed with their characters' abilities still in play. It really depends on what you're looking for in a fanfiction. If you like a slow - burn type of love story, you might have to dig a bit deeper to find those gems among the many available fictions.
Definitely Kakashi. Since he has a connection to both Naruto and Tobi (Obito), his presence can add a lot of depth. He can be the one who tries to bridge the gap between Naruto and Tobi, or he could be a source of conflict as he has his own history with Tobi.
Some tobi lemon fanfics could be centered around his backstory. Writers might create detailed accounts of his past, things that weren't fully explored in the original source material. This could include his early training days or his relationships with other characters before the main events of the story. These fanfics can add more depth to his character.
One interesting Naruto and Tobi fanfiction could be where Tobi reveals his true identity to Naruto earlier in the story. This would completely change the course of events and their relationship. Naruto might try to reason with Tobi, believing there is still good in him.
Love and friendship are also common themes. Some stories explore the budding romance between the reader and Tobi, how they fall in love despite the challenges. Friendship is also there, like when the reader becomes Tobi's closest confidant. Additionally, there can be themes of redemption. If Tobi has done some bad things in the original story, the fanfiction might show how the reader helps him redeem himself.
One possible plot could be that Tobi kidnaps Kakashi to gain some valuable information. Maybe he wants to know about the Sharingan secrets Kakashi has. Tobi could hold Kakashi in a secret lair and try to interrogate him.
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.