What are the new abilities Naruto might gain as he becomes mature in the fanfiction?

Well, if Naruto becomes a Sannin, he would surely gain some amazing new abilities. For one, he could inherit Tsunade's healing abilities. This would be a great addition to his skills as he could not only fight but also heal his comrades on the battlefield. In terms of Jiraiya, Naruto might be able to master more advanced forms of Rasengan, inspired by Jiraiya's own jutsu creativity. And from Orochimaru, he could get a better understanding of the chakra nature and how to manipulate it in more complex ways, like Orochimaru did with his snake - like jutsus.

One possibility is that he gains enhanced speed and stealth. As a chunin, he'd need to be more covert in his missions. He could learn to move so quietly that even sensors would have a hard time detecting him. And his speed could be on a level where he can quickly close the gap between him and his enemies without them realizing it until it's too late.

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.

Naruto would gain super strength. He could lift extremely heavy objects with ease, like mountains or large buildings in the Naruto world. He would also have super speed, enabling him to move faster than any ninja technique. And of course, he would be able to fly, which is a completely new ability in the Naruto universe.

Naruto might gain the power of shikai and bankai. Shikai is the first release of a zanpakuto's power, and bankai is the ultimate form. Naruto, with his determination and strong will, would strive to master these forms. Shikai could give him new attacks and defenses, while bankai could make him an extremely powerful force. For example, his bankai could combine his ninjutsu skills with the zanpakuto's power in a unique and devastating way.

He might gain enhanced physical strength like Bane. Bane was known for his brute force, so Naruto could have a similar boost, being able to overpower his opponents more easily in hand - to - hand combat.

One significant ability he could obtain is the power to enter a special sage mode unique to fox sages. In this mode, his appearance might change to incorporate more fox - like features. His speed would be incredible, enabling him to dodge attacks with ease. His ninjutsu could also be enhanced, for instance, his Rasengan might become larger and more powerful, infused with the energy of the fox sage.

He might gain enhanced senses like better hearing and smell, which are common for hanyous. This would help him in tracking enemies or sensing danger even before it's visible. Also, he could have increased physical strength and speed. His already impressive ninja skills combined with the hanyou powers could make him a formidable fighter in close combat.

He might gain the ability to teleport instantly across the village or even between different regions. This would be very useful for quickly responding to threats or attending important meetings. For instance, if there is an emergency on the outskirts of the village, he can be there in a blink of an eye.

He might gain the ability to teleport short distances. Since Kurama's chakra is so powerful, it could potentially warp space around Naruto for a quick teleport. Another new ability could be a more powerful chakra shield. With both halves of Kurama, he could create a shield that not only protects him from physical attacks but also nullifies ninjutsu to some extent.