One idea could be exploring the origin of the Ten - Tails in a different light. Maybe it was created by an ancient civilization for a noble purpose that got corrupted over time. Another could be a story where a young ninja discovers a hidden power within the Ten - Tails and has to learn to control it without being consumed by its dark energy.
In some fanfictions, the Ten - Tails could be a key to unlocking a new dimension. The protagonist might be on a quest to find out the secrets of this dimension and how the Ten - Tails is related to it. They could face many challenges along the way, like battles with other powerful ninja who also want to use the Ten - Tails for their own gains.
Perhaps in the fanfiction, the Zero Tails is a manifestation of the negative emotions of the ninja world as a whole. A group of young ninjas discover this and they try to find a way to purify the Zero Tails. They seek the help of old sages and learn ancient jutsu to attempt this purification, which could lead to a battle against those who want to keep the Zero Tails as a weapon of mass destruction.
One idea could be Naruto having a unique connection with the Nine Tails that allows him to access new forms not in the original series. For example, a form that combines his human features with more fox - like aspects in a more aesthetically pleasing and powerful way.
One idea could be exploring the Four Tails' backstory more in - depth. Maybe it has a connection to an ancient ninja clan that was long forgotten. Another is a story where the host of the Four Tails has to team up with an unexpected ally to control its power.
One idea could be a fanfiction where Naruto has to temporarily transfer the Nine - Tails' power to a fellow ninja to save the village. This would create an interesting dynamic as the other ninja has to quickly adapt to the power and the responsibility that comes with it.
Well, a possible plot for a 'naruto with tails fanfic' might involve Naruto using his tails to travel to different dimensions. In these dimensions, he could encounter alternate versions of his friends and enemies. He might have to use the unique abilities of his tails to find his way back home. Or perhaps his tails start to develop a mind of their own and he has to work with them rather than against them to become stronger. Maybe he discovers that his tails hold the key to unlocking a long - lost prophecy related to the Hidden Leaf Village.
One plot idea could be Naruto struggling to control the 4 - tails form in a new and dangerous mission. Maybe he has to fight an enemy that specifically targets his unstable state. Another could be his friends trying different ways to help him calm down when he goes 4 - tails, leading to some heart - warming moments of friendship.
One idea could be Naruto using the Nine - Tails' power to travel to different dimensions and encounter versions of his friends with different personalities. Another could be him training with the Nine - Tails to create new and unique jutsu that no one has ever seen before. Maybe he uses the power to go back in time and change certain events in the ninja world's history for the better.
Well, there could be a fanfiction where the Nine - Tails Chakra has a mind of its own and starts to communicate with Naruto in a more complex way. It could show him visions of the future of the ninja world and guide him to make choices that are different from what he would have done otherwise. This could lead to new alliances and a completely different path for Naruto and his friends in the story.
For a 'naruto of the nine tails fanfic', a great plot could involve the nine - tails sharing its ancient memories with Naruto. These memories could give Naruto insights into the history of the ninja world and new ways to use his power. Additionally, a plot where the nine - tails starts to develop its own emotions and opinions that conflict with Naruto's, leading to an internal struggle for Naruto, would be really interesting.
A great plot could be about a group of young ninjas who accidentally awaken the Ten Tails and then have to find a way to reseal it before it destroys everything. They could discover new jutsus and powers along the way. Also, what if the Ten Tails had a different form that was not known before, and the characters have to figure out how to deal with it.