In the fanfiction, Naruto could gain the power of enhanced perception. The Kyuubi's bloodline might give him the ability to sense things from a much greater distance, whether it's the presence of other ninja, hidden traps, or even changes in the environment. Additionally, he might have better control over his own emotions and be able to resist mind - control techniques more effectively. This is because the Kyuubi's bloodline could strengthen his mental fortitude, making it harder for enemies to manipulate his thoughts or feelings.
One potential power could be the ability to manipulate fire in a unique way. The Kyuubi has a lot of raw power and in a fem form, it might manifest as a different type of elemental control. Naruto could use this newfound power to create more powerful fire - based jutsus or even combine it with his existing techniques in a more effective manner. Another power might be enhanced speed. The Fem Kyuubi's bloodline could give Naruto the ability to move at blinding speeds, making him a more formidable opponent in combat.
In some fanfictions, Naruto might obtain the Kyuubi's bloodline through a special ritual. This could be a ceremony performed by a powerful shinobi or a sage who has the knowledge to transfer the essence of the Kyuubi's power into Naruto's genetic makeup, thus giving him the bloodline.
In some fanfictions, Naruto might obtain the bloodline through a magical or spiritual connection with the Fem Kyuubi. Maybe during a moment of extreme danger or a special ritual where the power of the Fem Kyuubi is transferred to him, allowing him to gain a new bloodline.
Naruto could gain the ability to manipulate fire in a unique way. Since the Kyuubi is associated with a certain element - like energy, it could translate into Naruto having a new form of elemental jutsu. He might also be able to heal faster. Kyuubi's chakra has shown to have regenerative properties, and with a bloodline, this could be enhanced in Naruto, allowing him to recover from injuries more quickly.
One possible power is the ability to see through illusions more easily. Since the Kyuubi is a powerful entity, a doujutsu from it could give Naruto an edge against genjutsu users. It could break through complex illusions that would otherwise trap him.
Well, if Naruto got a bloodline from Kyuubi in fanfiction, it could make him even more powerful. He might have new abilities like enhanced speed or strength related to the Kyuubi's nature. His appearance could also change, perhaps with some fox - like features. This would definitely change how he interacts with his friends and enemies. For example, Sasuke might view him as an even greater threat or rival, and his friends might be in awe of his new powers.
In some fan theories, it could be due to a unique chakra interaction. Maybe the Kyuubi's powerful chakra somehow mutates Naruto's own ocular abilities and triggers the emergence of the Sharingan. But this is just a wild fanfiction idea.
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.
Well, perhaps the bloodline could grant superhuman strength like Killer Croc has in the DC universe, which in the Naruto world might translate to being able to break through earth - style jutsu defenses more easily. Also, it could give the ability to swim at great speeds and hold one's breath for long periods, useful for underwater missions or battles near water sources in the Naruto world.
In fanfiction, Naruto's Uzumaki bloodline could grant him the power of chakra suppression. He could hide his own chakra signature completely, making it impossible for enemies to detect him. This would be a great advantage for stealth missions. Also, he could have the power to transfer his chakra to others in a more efficient way. For example, he could heal someone who is on the verge of death by sharing a large amount of his chakra without putting himself at too much risk due to his Uzumaki - enhanced chakra reserves.