In many such fanfictions, it could be a variety of deities. It might be an ancient and powerful god from Naruto's world's mythology that the story's author has chosen to insert. For example, it could be a god of elements like a super - powerful fire god, which could give Naruto even more control over his existing fire - based jutsu and new, more extreme abilities related to fire.
With his enemies, it would be a whole different story. They might be more cautious about attacking Naruto. Some might even try to find a way to use the god sealed in him for their own purposes. And Naruto's relationship with the hidden villages could also change. They might see him as a potential threat or a very valuable asset.
I'm not entirely sure if there is a specific fanfiction with exactly that premise. However, given the popularity of both Naruto and the concept of sealing powerful entities in Naruto's world, it's quite possible. Fanfiction writers love to experiment with combining different fictional elements, so it wouldn't be surprising if someone has written a story where Jenova is sealed in Naruto. You can try searching on popular fanfiction websites like Fanfiction.net or Archive of Our Own to find out for sure.
One interesting plot could be Naruto gradually learning to control the power of the god sealed within him. Maybe he discovers new jutsus or abilities that are unique to the god's power. For example, he might be able to manipulate time or space in a way that no other ninja can.
Well, Naruto might become more mysterious. Since Gaster is an unknown and rather enigmatic entity, Naruto could start having strange thoughts or powers that he doesn't fully understand at first. He might seem more withdrawn as he tries to figure out what's going on inside him, and his normal cheerful and straightforward personality could be clouded by the presence of Gaster.
It makes him more powerful, which could lead to overconfidence at first. But as he realizes the great responsibility that comes with the god's power, he becomes more mature. For example, he might be more cautious in battles, thinking not just about winning but also about the consequences of using the god - like abilities.
In some fanfictions, the main antagonist could be Naruto's own inner demons brought on by the presence of the wolf. These could manifest as self - doubt, fear, or a dark side of his personality that the wolf's power seems to amplify. So, in a way, Naruto has to fight against himself as well as any external threats.
His abilities would change in multiple ways. Firstly, his chakra control might be affected. Since Godzilla is a massive and powerful entity, it could disrupt Naruto's normal chakra flow. However, he could also learn to harness Godzilla's power within him. For example, he might be able to use Godzilla's raw strength to enhance his Sage Mode or even his Nine - Tails transformation. This could make him an even more formidable opponent. His speed could also be enhanced as Godzilla's power might give him a boost in his physical capabilities, allowing him to move faster and react quicker in battle.
He could gain the power of manipulation. Gaster might give Naruto the ability to manipulate space or time on a small scale. Maybe he could create small portals or slow down time for a short period during combat.
Well, if Cloud is sealed in Naruto in fanfiction, it could greatly enhance Naruto's power. Maybe he could control new types of jutsus related to cloud elements, like cloud - based attacks or defenses. This would make him even more formidable against his enemies.
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.