He might gain enhanced physical strength. Since the Kyuubi is known for its great power, Naruto could have a boost in his melee combat abilities. For instance, his punches and kicks could be more powerful, allowing him to take on stronger opponents more easily.
One possible new ability could be a form of Kyuubi - inspired chakra control. He could use the Kyuubi's chakra in more creative ways, like shaping it into unique forms for attacks or defenses. This would give him an edge in battles as it would be unexpected and difficult to counter.
Well, it could make some characters fear him. For example, those who don't understand the nature of his succession might be wary. But his friends, like Sasuke, might see it as just another aspect of Naruto. They've seen his determination before, and this new status could be seen as an extension of his power and the challenges he has to face.
Maybe through some kind of special training or a unique ritual. It could be that he discovers a hidden method within the ancient scrolls of his village.
He probably gains the ability to control the chakra of the Kyuubi more freely. This could mean enhanced strength, speed, and reflexes. He might also be able to use some of the Kyuubi's unique jutsu like the Tailed Beast Ball. His healing factor could be improved as well, allowing him to recover from injuries faster.
He might gain enhanced chakra control. Since he has the Kyuubi's soul, he could have better access to the Kyuubi's chakra reserves and be able to manipulate it more precisely. Maybe he could also gain some of the Kyuubi's natural abilities like better senses, especially smell, which could help him in tracking enemies or finding things.
If Naruto became an Ino fan due to Kyuubi's influence, he might gain some mental fortitude. Ino is good at mind - related jutsu, and Naruto could learn from her how to better protect his mind from enemy attacks. Maybe he'd start to develop a form of mental shielding similar to Ino's techniques.
In fanfiction, the fusion can completely transform Naruto's abilities. Firstly, his chakra control could reach a whole new level. With the Kyuubi's chakra, which is vast and powerful, he could perform long - range and large - scale attacks more easily. His ability to sense danger and opponents would also improve. The Kyuubi's instincts might add to Naruto's natural senses, making him more aware of his surroundings. Moreover, Naruto might gain the ability to transform into a more powerful form that combines his human features with some of the Kyuubi's characteristics, like having fox ears or a tail while still maintaining his humanoid shape, which would give him additional advantages in combat, such as better balance and agility.
It could also be a completely new character introduced into the fanfiction. A foreign ninja who was inspired by some of Danzo's ideas (not the bad ones) and comes to Konoha to take on the role of successor, bringing in new perspectives and ways of doing things.
At first, Naruto might see the Kyuubi as just a source of power. But as he starts to protect it, he realizes it's more of a partner. Their relationship evolves from a simple user - power source dynamic to a deep - seated friendship. He begins to understand the Kyuubi's emotions and past, which further cements their bond.
In this fanfiction, their relationship becomes more of a partnership. Instead of Naruto just using the Kyuubi's power, they work together as brothers. Naruto might start to understand the Kyuubi's feelings and motives better.
Naruto would gain some really cool (pun intended) new abilities. The ice - making ability would be the most prominent. He could form ice clones, similar to his shadow clones but with the added advantage of being made of ice and potentially having more durability. His sensory abilities might also be enhanced, as Esdeath has a good sense of her surroundings when using her powers. He could detect enemies hidden in the ice or snow. And, like I said before, the time - freezing power. This would allow him to analyze his opponents' moves during the frozen time and come up with the perfect counter - attack. It would add a whole new dimension to his combat skills.