One interesting fanfiction could be where Naruto has an unexpected and more powerful tailed beast transformation during a major battle. Maybe he combines the power of all the tailed beasts in a new way, surprising his enemies and allies alike.
Well, Naruto himself might still be a main character as he has a strong connection to the tailed beasts in the original series. He could be the one trying to understand and deal with the 10 - tailed beast in new ways.
In this fanfiction, the plot might involve Naruto being experimented on by some dark force. This experiment causes him to transform into a tailed beast in a way that's different from his normal jinchuriki forms. As he changes, he starts to view the world from a more primal perspective. He might even break away from the Hidden Leaf Village and the story could be about his journey to regain his sanity and his place among his friends and the village.
One interesting plot could be the exploration of the power dynamics when the 10 - tailed beast interacts with different ninja clans. Maybe it shows how they try to either control it or form alliances with those who can.
It could be Orochimaru. He has always been interested in power and the secrets of the tailed beasts. He might see Naruto's transformation into a tailed beast as an opportunity to study and use that power for his own evil purposes. He could try to manipulate Naruto in his new state, perhaps by using genjutsu or other underhanded tactics.
One interesting story could be about the unique bond between Naruto and one of the tailed beasts in a fan - created adventure. Maybe the tailed beast helps Naruto in a new and unexpected way, like using its power to open a portal to a hidden land filled with ancient ninja secrets.
One unique idea is that Naruto can transfer his tailed beast transformation ability to his friends temporarily. This could be used in a team - up situation where they need an extra boost in battle.
Naruto and the Nine - Tails (Kurama) are probably the most popular. Their relationship throughout the original series was so complex and full of development that it's a natural choice for fanfiction. Also, Naruto with Son Goku, the Four - Tailed Beast, has some popularity as they both have strong - willed and somewhat hot - tempered personalities which can lead to interesting interactions in fan - created stories.
One possible plot twist could be that Naruto's new form as a tailed beast gives him the ability to communicate with all the tailed beasts simultaneously. This could lead to him uniting them in a way that no one has ever seen before, and they might work together to bring about a new era of peace in the ninja world.
Yes, I recommend the novel," I Raise Tailed Beasts in Naruto World," to you. The main character, Ryoshimiya, transmigrated to the Naruto World and became a member of the Kiba Village. She awakened the Tail Beast System, but her own Tail Beast was in a strange shape, which made people very suspicious. This novel described the protagonist's growth in the Naruto world and his interactions with the number of tailed beasts. I hope you like my recommendation.๐