If Naruto has all bijuu in fanfiction, it's a huge game - changer. Firstly, his training and growth would be on a whole new level. He'd have to learn to balance the different natures and personalities of each bijuu. His opponents would have to come up with new strategies to face him. Moreover, it could open up stories about how he uses the bijuu to bring peace to the ninja world. Maybe he could use their power to stop wars and conflicts, or to protect the weak. It could also lead to interesting interactions with characters like Sasuke, as they might have different views on how to use such great power.
His power becomes extremely overwhelming. With all nine bijuu, Naruto gains access to an insane amount of chakra. He can perform massive jutsu without much strain. For example, his Rasengan could potentially be magnified to a scale that could destroy large areas with ease. Also, his physical abilities like strength and speed would be enhanced to superhuman levels due to the boost from the bijuu's power.
Well, it makes Naruto extremely powerful. He becomes like a force that no one can easily oppose. His chakra level skyrockets, and he can use the unique abilities of each bijuu. This changes the power balance as he can now handle threats that were previously too difficult, like taking on powerful villains single - handedly.
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.
One storyline could be Naruto using the bijuu powers to unite all the ninja villages. He could show off his power and convince them that working together is better. Another could be him facing off against a new, even more powerful enemy that is attracted by his collection of bijuu. Maybe a powerful demon from another dimension.
The story might progress with Naruto becoming a sort of super - protector. He could use the power of all bijuu to defend the Hidden Leaf Village from any threat.
One potential plot development could be that Naruto has to face new, more powerful enemies who are drawn to his newfound power. Another could be that he has to learn to control the combined power of all 9 bijuu, which might be a difficult and dangerous process.
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, Naruto could face several consequences. Firstly, the sheer amount of chakra from all the bijuu might put a strain on his body. He could experience physical exhaustion or even harm to his internal organs. Psychologically, he might have to deal with the voices and personalities of all the bijuu in his head. This could be a real challenge for him, as some of the bijuu might have conflicting natures. Also, in terms of his relationships, some people might fear him or be jealous of his new power. This could lead to a strain in his friendships and alliances. And from a political perspective, other ninja villages might see him as a threat and try to either control or eliminate him.
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.