Naruto himself is often a popular character in such fanfictions. Since he has a strong connection with the bijuus, especially Kurama, his time - traveling adventures can create really interesting stories. Another popular character is Sasuke. His power and his complex relationship with Naruto can add depth to time travel plots.
One interesting plot could be the main character traveling back in time and preventing the initial capture of the bijuus. This would completely change the power dynamics in the Naruto world. Another could be a character using time travel to team up with past jinchuriki to fight a new, greater threat.
A plot twist could be that the bijuu themselves have a collective consciousness that Naruto doesn't expect when he absorbs them. This consciousness could start to influence Naruto's actions during his time travels. For instance, they might guide him towards certain events or people that they believe are important for their own reasons. Maybe they want to correct some past wrongs in the ninja world that were related to their existence. This would add an interesting layer to the story as Naruto has to deal with not only the power of the bijuu but also their will.
In fanfiction, if Naruto is half - bijuu, it could mean he has enhanced physical abilities. For example, he might have greater strength and speed like a full - bijuu. His chakra reserves could also be much larger, allowing him to perform more powerful jutsu for longer periods.
It could have a huge impact. With Naruto absorbing all the bijuu through time travel, the power balance among the ninja villages is completely disrupted. Some villages that relied on their own bijuu for protection or status might lose their advantage. This could lead to political unrest as they try to find new ways to assert themselves. Also, the overall perception of power in the ninja world would change. Naruto would become an extremely powerful and perhaps feared figure, which could either inspire others to follow him or try to bring him down.
In many Naruto fanfictions, if Naruto has three bijuu, they could be the Nine - Tails (Kurama) which he already has in the original series, perhaps the Eight - Tails (Gyuki) as it has a connection with Naruto's world and Akatsuki's hunt for the bijuu. And another could be the Three - Tails (Isobu). However, it really depends on the specific plot and creative direction of the fanfiction.
It could be an ancient sage. In Naruto lore, there are sages who have had a great influence on the world. An ancient sage could be the one who created or fathered the bijuu. Maybe he had some great power and knowledge that allowed him to bring the bijuu into existence.
It could be Shukaku. Since Shukaku was one of the first bijuu introduced in the series and has a sand - based power, it would be an interesting addition to Naruto's arsenal. Naruto's positive and energetic personality could also have an impact on Shukaku's usually grumpy and solitary nature.
Well, having two bijuu would likely make Naruto extremely powerful. He could potentially combine their unique chakra natures and abilities in combat. For example, if one bijuu has a fire - based ability and the other has a water - based one, he might be able to create new and unexpected jutsu by mixing them. Also, it would change his standing in the ninja world. People would probably be more in awe or more fearful of him, depending on their stance towards Naruto.
In 'fem bijuu are possessive of naruto fanfiction', Kurama is likely to be a very prominent fem bijuu. Given her power and the fact that she has been inside Naruto for a long time, her possessiveness can really shape the story. Additionally, Matatabi, the Two - Tailed Cat, could also be a notable fem bijuu. Her feline nature might add an interesting layer to her possessiveness towards Naruto, perhaps making her more sly and protective in a different way compared to Kurama.