One idea could be a fanfic where Naruto discovers a new and powerful summon that no one has ever seen before. This summon could have unique abilities that help Naruto in a crucial battle against a powerful enemy.
One idea could be a story where Naruto uses the Saimin Jutsu in a creative way during a crucial battle. Maybe he uses it to make the enemy see illusions of their worst fears, causing them to be paralyzed with fear and unable to fight back effectively.
In naruto kuchiyose fanfiction, an interesting aspect could be the relationships between Naruto and his summoned creatures. For instance, he might form a deeper bond with one of his summons, like the toads. This could lead to the summon having a greater influence on Naruto's growth as a ninja. Additionally, some fanfictions might explore how Naruto's kuchiyose jutsu evolves over time, perhaps allowing him to summon larger and more powerful versions of his usual summons.
Perhaps Naruto hides his jutsu because he's being spied on by an unknown enemy within the village. He doesn't want to expose his new and powerful techniques until he can figure out who the spy is. So he acts like he's still relying on his old moves during training and small skirmishes.
You could also write a fanfic that delves into the origin of the Oiroke no Jutsu. Maybe it was a technique passed down in the Uzumaki clan, and Naruto discovers some hidden aspects of it. This could involve exploring old scrolls or having a conversation with an elder who knew about its true nature.
Gaara could also be part of the fanfic. Since he has his own unique abilities related to sand, there could be an interesting interaction between his powers and Naruto's summoned creatures. For example, Naruto could summon a water - based creature and they could team up with Gaara to fight an enemy that is strong against both sand and water.
Well, perhaps a plot where the harem no jutsu is used not just for comical effect but to actually solve a complex political situation in the Naruto world. The various characters in the 'harem' could use their unique skills and influence to bring about peace. It could also be interesting to see how Naruto manages this new dynamic among the characters in his 'harem' and how it changes his relationships with them on a deeper level.
Here's a cool idea. In a 'Naruto Shadow Possession Jutsu Fanfiction', the jutsu could be passed down through generations in a family, but with a curse. Every time it's used, it slowly drains the user's life force. A young heir of this family has to find a way to break the curse while still using the jutsu to protect their loved ones. Another plot could be that an enemy uses the Shadow Possession Jutsu to create an army of shadow - controlled puppets. Naruto and his team must find a way to stop this without harming the people who are being controlled. And then there could be a story where the jutsu is combined with a new type of chakra, creating a whole new set of abilities that the main character has to master.
One idea could be that Naruto accidentally uses the Reverse Harem Jutsu on himself instead of an opponent. He then has to deal with the chaos of multiple versions of himself with different personalities. For example, one might be super confident, another shy, and they all have to work together to solve a problem in the village.
One idea could be a story where the main character uses Oriko Jutsu in a unique way to communicate with the Kyuubi. Maybe they form an unexpected alliance to face a new, powerful enemy in the Naruto universe.
One idea could be a story where Naruto discovers a new, ancient space - time jutsu that allows him to travel to alternate universes. In these universes, he meets different versions of his friends and enemies, and has to find a way to return home while also dealing with the chaos caused by the jutsu's power.