A possible plotline is that Sasuke's journey takes an unexpected turn due to this 'destined to happen' concept. He might find out that his actions are not only about his revenge but are part of a bigger plan. Maybe he has to team up with old enemies to face a common foe that was always meant to be defeated by their combined efforts.
Naruto would likely still be one of the most important characters. His role as a main protagonist in the original Naruto series means he'd probably play a crucial part in any fanfic with a 'destined to happen' theme, whether it's about fulfilling a new prophecy or saving the world in a different way.
A possible plotline is a gender - bent Naruto having to prove herself in a male - dominated ninja society. She could form an all - female ninja team and take on missions that are typically thought to be for male - only teams. This would show her strength and determination in a different light compared to the original Naruto story.
One interesting plotline could be about Naruto unlocking a new and extremely powerful form in the 'naruto fury fanfic'. This form might be a result of his intense fury and determination, allowing him to face off against enemies he couldn't before.
One interesting plotline could be Naruto coming back reanimated and having to face new enemies that his old friends can't handle alone. His reanimated state might give him unique powers or abilities that change the course of battles.
One interesting plotline could be the exploration of Onikage's backstory within the Naruto universe. Maybe he has a hidden connection to a powerful clan that was long forgotten.
One interesting plotline could be the exploration of the unique culture and history of the Mist Village within the fanfic. Maybe it delves into the training methods of Mist ninjas that are different from other villages.
One interesting plotline could be about Naruto exploring an alternate universe within the Samsara concept. Maybe he discovers new powers or meets different versions of his friends.
One interesting plotline could be Naruto's discovery of new and powerful sealing techniques. He might use these to defeat enemies in unique ways, like sealing away their chakra sources. For example, he could develop a seal that can nullify the effects of a powerful jutsu by sealing the energy that fuels it.
Perhaps Naruto controls Zetsu to help him in battles. Zetsu could act as a distraction while Naruto sets up his more powerful jutsu. For example, Zetsu could split into multiple forms and confuse the opponents, giving Naruto an opening to attack.
One interesting plotline could be Naruto adjusting to civilian life after retiring. He might struggle with the boredom of not having the constant action and purpose he had as a shinobi. Another could be him mentoring the next generation in a more laid - back way, passing on his wisdom without the pressure of active duty.