One possible plot could be Naruto dying heroically in a battle and coming back as a ghost to guide his friends. For example, he could help Sasuke understand the true meaning of friendship from beyond the grave.
A Naruto is a Ghost fanfic could have a plot where Naruto is killed by an unknown enemy. As a ghost, he discovers that his death was part of a larger conspiracy. He then uses his ghostly abilities, like invisibility and intangibility, to uncover the truth. Along the way, he might encounter other spirits from the Naruto world's past who give him advice or help him on his quest. And he would also be trying to protect the village and his loved ones from the shadows in his new form.
One idea could be that the main character becomes a ghost after a tragic event in the Naruto world. Maybe they were killed during a battle and now they haunt the Hidden Leaf Village. They could use their ghostly powers to protect their friends from unseen threats, like spying on enemy ninjas without being detected.
One possible plot for 'naruto becomes a ghost fanfiction' is that Naruto sacrifices himself to save the village. As a ghost, he discovers new abilities like being able to possess people or objects. He uses these powers to protect Konoha from threats that the living ninjas can't handle. He might also have to deal with his own unfulfilled desires and relationships in this new ghostly form.
In a 'naruto is half ghost' fanfiction, the plot might center around Naruto's struggle with his dual nature. He could be shunned by some in the village who fear his ghostly side. Meanwhile, he has to learn to control his new powers. For example, he might discover he can travel to a spirit realm and has to figure out how to use that to his advantage, like getting intel on enemies or finding lost jutsu.
In a 'Naruto is the Raikage' fanfic, the plot could be that Naruto is transported to an alternate universe where he is the Raikage. He has to quickly adapt to the Cloud Village's culture and politics. He might face a powerful enemy that is targeting the Cloud Village specifically. Naruto then uses his experience from Konoha and his Uzumaki heritage to find a way to defeat the enemy. Meanwhile, he tries to bridge the gap between the different clans in the Cloud Village and bring about a new era of peace and prosperity. There could be a lot of sub - plots involving his relationships with the Cloud ninja, his attempts to improve the village's infrastructure, and his struggle to maintain his own identity while taking on this new role.
One possible plot could be that Naruto somehow gets transported to a world where Deathstroke exists or vice versa. Naruto then has to adapt to Deathstroke's way of fighting and living. He might face challenges where he has to use his new - found Deathstroke - like skills to survive against enemies he's not used to.
One possible plot could be Naruto using his scientific knowledge to improve the ninja world. For example, he might develop new jutsu that are based on scientific principles rather than just chakra manipulation. He could study the properties of different elements in a scientific way and create more powerful and efficient attacks.
In a 'naruto is nero fanfic', perhaps Naruto is mistaken for a powerful being in Nero's world. Nero might initially be cautious of Naruto but then realize they share a common goal of protecting the weak. They could team up to fight against a powerful dark force that threatens both their worlds, with Naruto using his Rasengan and Nero using his Devil Bringer in combination.
Well, if there was a 'naruto is vanitus fanfic', it could be about Naruto somehow inheriting the powers or characteristics of Vanitus. Maybe Naruto has to deal with the new - found powers and how they affect his relationships in the Naruto world, like with Sasuke and Sakura.
Well, it could be about Naruto being a huge fan of Ganondorf's power and trying to incorporate some of his dark and dominating traits into his own ninja style. Maybe Naruto starts to study Ganondorf's strategies and uses them in battles against tough opponents in the ninja world.
Maybe Naruto uses his rap skills to spread his ninja way. He could rap about his training, his friends, and his determination to become Hokage. His raps might inspire other characters in the Naruto universe.