One idea could be a story where Obito's mask holds a hidden power. For example, it could be a key to an ancient jutsu that was sealed away long ago. Another plot could involve a character trying to steal the mask for its significance in the ninja world.
A really interesting plot could be that the mask has a connection to Obito's past self before he turned into the person he became in the main Naruto storyline. Maybe it was a gift from someone important, and as the fanfiction unfolds, we learn more about his true nature through the history of the mask. This could involve flashbacks and revelations that change how we see Obito in this new fictional context.
Perhaps in the fanfiction, the mask is actually a conduit for Obito to communicate with a long - lost clan. The clan's secrets are locked within the mask, and Obito has to figure out how to unlock them without falling prey to the dark forces that also want to use the clan's power for their own evil purposes. As he delves deeper, he discovers that his own destiny is intertwined with this clan in ways he never expected.
One idea could be a story where Naruto somehow travels back in time and meets a younger Obito. He tries to change Obito's path before he turns to the dark side. This could involve Naruto showing Obito the true meaning of friendship and the value of the Hidden Leaf village.
One idea could be that Female Obito is a hidden shinobi from a forgotten clan. She teams up with Naruto to uncover a conspiracy within the Hidden Leaf. Their journey involves facing off against rogue ninjas who are trying to steal an ancient artifact that could change the balance of power in the ninja world.
One idea could be that fem Naruto and Obito are from different clans but are forced to work together on a mission. They start off disliking each other due to their clans' past rivalries. But as they face challenges during the mission, they gradually come to understand and respect one another. Another plot could be that in a different universe, fem Naruto has the power to see Obito's past and tries to change his fate. She becomes his friend and tries to guide him away from the dark path he took in the original story.
Another plot could involve Obito being reborn in Naruto's world at a different time. He has no memory of his past life initially. Naruto meets him and they become friends. As Obito starts to regain his memories, he has to decide whether to continue on the path of his previous self or to embrace the new relationships he has formed with Naruto and the others. It could lead to a great internal struggle within Obito.
Maybe the skull mask was once worn by a powerful and long - forgotten ninja clan. In the fanfiction, the main character stumbles upon the mask and is then hunted by other clans who fear the power it holds. The story could revolve around the main character's struggle to keep the mask safe while also trying to figure out how to use its power to protect themselves and their village.
A great plot idea could be that there is a masked figure who seems to be causing chaos in the village. Naruto suspects it's someone he knows, but as he digs deeper, he realizes it's an imposter using the identity of a well - liked shinobi. Or perhaps the mask is a symbol of a long - forgotten clan, and Naruto is the key to unlocking its secrets. This could lead to adventures where he has to travel to old clan ruins and face challenges related to the clan's past. Also, the masked character could be a time - traveler from Naruto's future, trying to change something in the past.
One idea could be that the reborn character tries to prevent Obito's fall to the dark side. They could use their knowledge of the future to stop Madara from manipulating him. For example, they might intervene during the battle where Obito was thought to be dead and expose Madara's true intentions early on.
Maybe the OC is a time - traveler who accidentally lands in Obito's time. She knows about his future actions but instead of trying to stop him right away, she tries to understand his pain. This leads to a complex relationship where Obito is both intrigued and afraid of her knowledge.
A plot where Sakura discovers a hidden connection between Obito and an ancient medical jutsu that was lost. They then embark on a journey together to find more about it, facing various challenges along the way. During this time, they gradually develop a mutual respect and a bond that is different from their normal relationships with others. This journey could also involve encounters with old enemies and new allies, all while exploring the depths of their own capabilities.
In a fanfiction, Obito might be sent on a mission by some unknown force to watch over Baby Naruto. As he does, he starts to question his own beliefs. Naruto's pure and unwavering will even as a baby might start to chip away at Obito's hardened heart. This could lead to Obito trying to influence Naruto's growth in a positive way, like teaching him some skills secretly without Naruto knowing it was Obito.