If Naruto had the gura gura fruit in a fanfiction, his character would change in several ways. His confidence might grow even more as he realizes the potential of this new power. However, he would also face new moral dilemmas. For instance, he has always been about protecting his friends and the village, but the gura gura fruit's power is so great that he could potentially cause harm to innocent people if he's not extremely careful. So he would have to be more self - reflective and learn to control his impulses better. Also, he might become a target for more powerful enemies who want to either steal the fruit or eliminate him to prevent him from becoming too strong.
Naruto would become more powerful, and this might make him a bit more cautious. He's used to his regular ninja abilities, but the gura gura fruit's power is on a different level. He might be more hesitant in battles at first, not wanting to accidentally cause too much destruction with the fruit's earthquake - causing ability.
Naruto's character would change quite a bit. Firstly, he would be more aware of his new - found strength. The gura gura fruit gives him the ability to create massive destruction, which is different from his usual ninjutsu. This could make him more serious in some ways. He would also need to adapt his fighting style. Instead of relying solely on his shadow clones and Rasengan, he would have to incorporate the power of the gura gura fruit. And since the power is so unique, he might start to see the world of ninjas in a different light, realizing that there are powers out there that are far beyond what he has known. He might also become more of a loner at times, as he tries to master the fruit's power without endangering his friends.
His self - confidence might change. On one hand, having this new powerful ability from the Gura Gura Fruit would boost his confidence. But on the other hand, he would also realize that he has a huge responsibility with these powers. He might become more introspective, thinking about how to use the power for good and not let it corrupt him, like how he was always careful with the power of the Nine - Tails inside him.
In a fanfiction about Naruto, the Gura Gura Fruit, and the Third Shinobi War, perhaps the Gura Gura Fruit is a new, mysterious element introduced into the war. Naruto, being the curious and adventurous ninja he is, might be the first to discover it. His friends and allies could be initially wary of this strange power, but as Naruto learns to control it, they see its potential in turning the tide of the war against powerful enemies such as Orochimaru or the Hidden Stone Village's forces.
One possible plot could be Naruto somehow obtaining the Gura Gura Fruit. He then has to learn to control its powers while still maintaining his own ninja skills. For example, he might accidentally cause earthquakes during battles at first, but as he masters it, he combines the fruit's power with his Rasengan, creating a super - powerful attack.
Naruto could use the Gura Gura Fruit to create huge tidal waves in battles near water sources. This would be a great advantage against enemies not used to fighting in water. For example, if facing the Sand Village ninjas, he could flood the desert battlefield, disrupting their attacks and movements.
In this fanfiction, Naruto with the Gura Gura Fruit might face a new type of antagonist. This antagonist could be someone who is also after the power of the fruit or someone who has a power that can counteract Naruto's new abilities. Naruto would have to figure out how to use the Gura Gura Fruit in combination with his existing ninja skills, like his shadow clones. He could create clones and then use the fruit's power through them to launch multiple attacks simultaneously, which would be a very interesting development in the story.
Their relationship could become stronger. Kushina, with the Gura Gura no Mi, would be an even more powerful protector. Naruto would look up to her even more, and they would bond over the new power she has. He might ask her for training tips on how to use such a powerful ability.
One possible plot could be that Kushina somehow gains the powers of the Gura Gura no Mi. She could use it to protect Naruto from various threats in the Naruto universe. Maybe she could create powerful shockwaves to fend off enemies like the Akatsuki. Naruto, seeing his mother's new power, would be inspired to train harder and learn how to combine his own jutsu with the power of the Gura Gura no Mi.
He would likely be more isolated at first. The Magu Magu Fruit powers are different from normal ninjutsu. His friends might not understand it fully, and he would need time to master it alone. This would make him more introspective, but as he gets better control, he would start to share his knowledge and use it for the good of the village. Also, his fighting style would change drastically. Instead of relying solely on his shadow clones and Rasengan, he would incorporate the heat - based attacks of the Magu Magu Fruit, making him a more versatile fighter.
Naruto might become more cautious. Guns are very different from ninja tools, and one wrong move could be fatal. So he'd have to think twice before acting impulsively, which is a big change from his usual head - first approach.
His relationship with his friends might change. They would see him as even more of a powerhouse. Some might be in awe of his new power, while others, like Sasuke, might feel a bit of rivalry. Naruto would also have to learn to control the power of the fruit, which could be a struggle at first. This journey of self - control would make him more mature and responsible. He'd understand the importance of not misusing such a powerful ability and would strive to use it for the good of Konoha and his friends.