One idea could be that the ten - tailed wolf has a special connection with Naruto's chakra nature, perhaps enhancing his already powerful abilities in a new and unexpected way. For example, it could give him the ability to control a new type of elemental jutsu.
Maybe the ten - tailed dragon has a consciousness of its own and forms a bond with Naruto. It could teach Naruto some long - lost ninja techniques that were once used to defeat great evils. This would make Naruto even more powerful and give him an edge in his fight against stronger foes.
One idea could be exploring the ten - tailed beast's origin in more depth. Maybe it has a hidden past or a connection to an ancient civilization that has been long forgotten in the Naruto universe.
Well, it could be that Naruto, as a ten tailed wolf, has to hide his true form from the villagers at first. Then, as the story progresses, he discovers new powers related to his ten - tailed wolf form that help him in battles against stronger enemies.
One idea could be the discovery of an 11th tailed beast that has been hidden away for centuries. The main characters in Naruto then have to figure out how to deal with this new and powerful entity. Maybe it has a unique ability that disrupts the existing balance of chakra in the ninja world.
One interesting plot idea could be that Naruto has to find a new way to bond with the Ten - Tailed Fox. Maybe the fox's power starts to go out of control and Naruto has to enter its mind - scape to calm it down. Another idea is that an enemy tries to steal the Ten - Tailed Fox from Naruto and he has to fight to keep it.
One idea could be exploring how Naruto's relationship with the tailed beasts changes when he has the power of the 10 - tailed beast. Maybe he struggles to control it at first and has to learn from the other tailed beasts how to manage such immense power.
One idea could be exploring the ten - tailed demon's origin from a different perspective. Maybe it was created as a result of an ancient war between gods. Another could be a story where the main character has to form an unexpected alliance with the ten - tailed demon to save the ninja world from a new, greater threat.
One idea could be Naruto having a hard time controlling the transformation at first. He might accidentally cause chaos in the village. Another could be that his friends try to reach out to the Nine - Tailed Fox within Naruto to understand it better. Maybe Naruto starts to gain new powers from the fox that are unique to this fanfic scenario.
It could be a rogue ninja who wants to capture the ten - tailed wolf for its power. He might be someone who was once shunned by the ninja village and now seeks revenge by obtaining this ultimate power source.
Kakashi is another common character. His wisdom and experience can play a big role in guiding Naruto when dealing with the ten - tailed wolf. He might be the one who has some knowledge about this creature from old ninja texts or legends.