The main character is Naruto for sure. But other characters like Jiraiya might play a significant role. Jiraiya could be the one to guide Naruto in controlling the four - tails' power. Also, characters from the Akatsuki might be main antagonists. They would be interested in Naruto's new power and try to capture or use him for their own purposes, like Pain or Itachi.
Well, in this fanfiction, it might be that Naruto's transformation into the four - tails form reveals some hidden secrets about the Nine - Tails' origin. This could lead to a whole new adventure as he tries to uncover more about it. Also, perhaps the four - tails form has a different set of abilities compared to what we've seen before, which makes for exciting battles and challenges for Naruto to overcome.
Naruto could use his Four Tails form to fight a new and powerful enemy that the normal ninja of the Hidden Leaf can't handle. For example, an enemy with the ability to nullify regular chakra attacks.
When Naruto goes full nine - tails in fanfiction, it often means a significant shift in the story's dynamics. His new power level can disrupt the existing power balance in the Naruto universe. He might attract the attention of more powerful and hidden enemies who see him as a threat. At the same time, he could also become a symbol of hope for those who are oppressed. For instance, if there are other villages being bullied by a stronger force, Naruto in his full nine - tails state could come to their rescue, thereby changing the political and social landscape of the Naruto world.
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 story where Naruto has more control over his Four Tails form earlier than in the original series. He could use it to protect the Hidden Leaf in a new and unexpected way, perhaps by combining it with some new jutsu he's created on his own.
Well, there are several places. Firstly, Naruto - related forums often have sections for fanfiction. Members share their own works or recommend good ones. Another option is Reddit. There are Naruto subreddits where fans might post or discuss Four Tails fanfictions. You have to dig a bit, but it can be rewarding.
In certain fanfiction, Naruto is indeed the Ten - Tails. This could be a really cool concept as it combines Naruto's already powerful nature with the ultimate power of the Ten - Tails. It might lead to stories where Naruto has to struggle with the dark side of such power, or he could use it to bring about a new era of peace in the ninja world. Maybe he would have to face off against old enemies who are now even more afraid of his new - found strength.
One possible reason could be some kind of strange chakra infusion. Maybe he comes into contact with a powerful and mysterious chakra source that mutates his body in a way that causes tails to grow. Another reason might be related to some ancient curse or prophecy. It could also be the result of a new jutsu he attempts that goes wrong and has unforeseen physical consequences.
Maybe through new jutsu or abilities. The fanfiction could give Naruto some unique power that allows him to communicate or negotiate with the Nine - Tails on a different level. He could use this power to show the Nine - Tails a different perspective, like the potential for harmony between them instead of constant struggle.