In this fanfiction, Naruto could control all the tailed beasts because of his unique chakra nature. His chakra is very special and has a high compatibility with the tailed beasts' chakra. Also, his experiences with Kurama might have given him insights on how to handle other tailed beasts. He probably communicates with them on a spiritual level and convinces them to work together with him.
Well, in many fanfictions, Naruto might use his strong will and the power of his Uzumaki heritage. His natural chakra reserves are huge, which helps. He also has a deep understanding of friendship and the tailed beasts' pain from his own experiences. So, he can connect with them on an emotional level and gradually gain their trust, thus being able to control them.
One interesting storyline could be about the tailed beasts forming an alliance outside of the control of humans. They might work together to protect their own kind and the world in a different way than the shinobi. For example, they could create their own hidden land where all chakra - based creatures are welcome.
In many fanfictions, the tailed beasts' personalities are shaped by their experiences. The Five - Tailed Horse is usually depicted as noble and proud. It has a certain elegance in the way it behaves. The Six - Tailed Slug is more nurturing and gentle, perhaps because of its slug - like nature. The Seven - Tailed Horned Beetle is often seen as mysterious and a bit aloof. It keeps to itself and doesn't easily open up. When it comes to the relationship with Naruto, these personalities play a big role. For example, Naruto might have an easier time getting along with the more friendly - natured tailed beasts at first, while having to work harder to understand and befriend the more reserved ones.
In such a fanfiction, Naruto would likely be extremely powerful. With all the tailed beasts' chakra at his disposal, he could easily overpower most foes. He might be able to perform new and incredible jutsu that were previously unimaginable. For example, he could combine the unique abilities of each tailed beast to create a super - attack.
If Naruto gets all the tailed beasts in the fanfiction, it would change the power dynamics completely. He could use their unique abilities in combination. For example, the Shukaku's sand control along with the Nine - Tails' chakra. This would make him a force to be reckoned with not only in combat but also in terms of politics and diplomacy in the ninja world. Other villages might see him as a threat or as a new leader to follow. And his relationships with his friends and allies would also evolve, as they would have to adjust to this new, super - powerful Naruto.
Naruto's relationship with the other villages would be transformed. Some villages might be afraid that he would use the power of all tailed beasts against them. However, villages like Iwagakure, which had a history of conflict with Konoha, could now see Naruto as a unifying force. The younger generation in all villages would probably idolize him more than ever, seeing him as a symbol of ultimate power and justice.
Another way is through shared experiences. If they face a common enemy together, like an evil organization that wants to capture all tailed beasts, they would have to rely on each other. This would lead to deeper understanding and stronger relationships as they fight side by side and protect one another in the face of danger.
Well, in such a fanfiction, the reader having all the tailed beasts could lead to a really complex plot. First, they would have to deal with the internal struggle of controlling such immense power. Maybe they start as an outcast in the ninja world because people fear their power. But as time goes on, they learn to use the tailed beasts' powers for good. They could form alliances with different villages, using the power of the tailed beasts as a deterrent against common enemies. And they might also discover secrets about the origin of the tailed beasts that no one else knew, which could change the whole perception of the ninja world.
Kurama is often a very popular character. As the Nine - Tails, he has a long history with the main Naruto storyline and his complex relationship with Naruto makes him interesting in fanfiction. He has a lot of power and a fiery personality.