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.
Yes, in some fanfictions, Naruto is often depicted as having a very special connection to the Nine - Tails that goes beyond the normal relationship in the original story. For example, he might be able to fully control the Nine - Tails' power in ways not shown in the canon, or they could have a mental bond that allows for unique forms of communication and cooperation.
In fanfiction, Naruto's protectiveness towards the Nine - Tails can stem from multiple reasons. Firstly, he has had a long journey of co - existing with it. They have a symbiotic relationship now. Secondly, Naruto has seen the power of the Nine - Tails and how it can be misused by others. He doesn't want that to happen. He also respects the Nine - Tails as a powerful entity. When it comes to threats against the Nine - Tails, Naruto uses his skills and his bond with it to safeguard it. He might even negotiate with others on behalf of the Nine - Tails to ensure its safety and well - being.
Well, in a fanfiction where Naruto becomes the zero tails, it could open up a whole new world of storytelling. The zero tails has a mysterious origin and nature. Naruto's transformation into it could mean a shift in the power balance in the Naruto universe. His relationships with other characters like Sasuke and Sakura would also be affected. For example, they might be initially afraid or suspicious of his new form. And Naruto himself would need to learn how to use the zero - tails' power for good, perhaps by finding a way to combine it with his existing values and ninja skills.
Another cool plot twist could be that the Ten Tails has the ability to split into multiple smaller entities, each with its own unique power. This would force Naruto and his friends to come up with new strategies to deal with these new threats. And it might also lead to some of these smaller entities turning good and helping Naruto in unexpected ways.
Sasuke could be a main character in a Naruto 11 Tails Fanfiction. He has always been Naruto's rival and equal in many ways. His skills and knowledge of the ninja world could be crucial in dealing with the 11 - tails. Maybe he would have a different perspective on how to handle the situation compared to Naruto.
A good Naruto Three Tails fanfic often has a strong understanding of the source material. It should accurately portray the nature and abilities of the Three - Tails. For example, it might describe how the Three - Tails' chakra is different from other tailed beasts.
One implication is the change in power dynamics. If Naruto is the Nine - Tails, he would be incredibly powerful, which could lead to different story arcs where he is either feared or revered. He might also face new enemies who are interested in his unique form.
In this fanfiction, the 11 - tails could be a symbol of a long - forgotten power. It might be linked to an ancient prophecy. Naruto would be drawn into the mystery of the 11 - tails. Along the way, he would face many challenges, like dealing with those who fear the power of the 11 - tails and want to destroy it without understanding it. He would have to convince them that there is a better way, perhaps by showing that the 11 - tails can be a force for good if properly controlled.