One interesting plotline could be the exploration of the Demon of the Mist's backstory. Maybe it reveals how the demon came to be associated with the Mist Village in the first place. Another could be a story where a character has to face the inner demons inspired by the Demon of the Mist and overcome them through self - discovery and growth.
In this fanfiction scenario, Naruto might have to adapt to the harsh and secretive ways of the Mist. He could use his new status to bring about change. Maybe he'd combine his own ninja way with the Mist's traditions, like using his shadow clones in unique Mist - style assassinations. He could also face a lot of internal conflict as the Demon of the Mist is often associated with darker deeds, while Naruto is a hero at heart.
If Naruto becomes the Demon of the Mist in fanfiction, he might start to lose his sense of self. The title 'Demon of the Mist' implies a certain level of malevolence and mystery that is quite different from Naruto's usual sunny disposition. His ninja way would be severely tested as he tries to balance the new, darker identity with his old values. Maybe he'd be forced to fight against his former allies who see him as a threat now. Also, his appearance could change to something more in line with the image of a demon, which would be a shock to those who know him well.
Often, Naruto himself is involved. Since it's in the Naruto universe, he might be the one to encounter the Demon of the Mist and try to figure out what to do about it. Also, characters from the Mist Village like Zabuza or Kisame could be main characters as they have connections to the Mist and its secrets.
Naruto's character would develop in many ways. Firstly, he'd have to face the stigma associated with being the Demon of the Mist. This could make him more determined to prove himself. He'd also learn about the history and secrets of the Mist, which would add to his knowledge and wisdom. His relationships would change too. Some might fear him, while others might see him as a chance for the Mist to change. Overall, he'd grow into a more nuanced and adaptable character.
His powers would likely incorporate more water - based elements. He might be able to control mist in ways that are more powerful and sinister than normal. For example, he could create mist that not only obscures vision but also drains the chakra of those who are trapped in it. His physical abilities could also be enhanced in a way that is more in tune with the Mist's fighting style, like being more stealthy and unpredictable in combat.
One idea could be that Naruto is sent on a mission to the Hidden Mist Village and gets separated from his team. He then has to adapt to the Mist Ninja ways to survive. He might learn their unique jutsu, like some water - based techniques, and form unexpected alliances with Mist Ninja who admire his determination.
There's a fanfiction called 'Rising in the Mist'. In this story, a previously unknown character in the Mist Village rises to power. The author does an excellent job of creating a believable backstory for the character and the political intrigue within the village makes it a really engaging read.
One common theme is the exploration of the unique ninja techniques of the Mist Village. Another is the complex relationships among the Mist ninjas. And often, there's the theme of redemption or self - discovery for characters from the Mist.
One common theme is mystery. Since it involves something 'missing' from the Mist, there's often a sense of intrigue about what happened. Another could be adventure, as characters go on a quest to find out what's missing.