One interesting idea could be the exploration of new powers. When Naruto merges with the Bijuu, he might gain unique abilities that are a combination of his own skills and the Bijuu's powers. For example, he could have enhanced strength and speed, along with the ability to use new types of jutsu that are based on the Bijuu's nature. Another aspect could be the impact on his relationships. His friends might view him differently, and he would have to deal with the newfound power and the responsibilities that come with it.
Naruto's character development in this type of fanfiction often involves becoming more mature. With the power of the Bijuu, he has greater responsibilities. He realizes that his actions now have a much bigger impact. He may also become more confident, as the Bijuu's power gives him an edge in battles. But at the same time, he has to be careful not to let the power corrupt him.
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.
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.
Naruto might be initially shocked. He has always seen the bijuu as powerful entities, not as potential mates. But being Naruto, he would likely approach the situation with his usual kindness and try to understand their feelings.
Naruto could face several challenges. Firstly, the mental strain of controlling such powerful entities. The bijuu have their own consciousness and desires, and keeping them in check mentally can be exhausting. Secondly, there's the issue of mastering different forms and abilities of the bijuu. Each bijuu has unique powers, and learning to utilize them effectively without losing control is no easy feat. Moreover, he may face social challenges as some in the ninja world may not trust him with this much power and try to undermine his control.