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.
One possible new ability is the power to manipulate time on a small scale. With the full power of Kurama, Naruto's chakra could be so potent that it could slightly distort time in his immediate area. He could also gain the ability to heal himself more rapidly. Kurama's chakra has always had a regenerative aspect, and with both halves, this ability would be enhanced. He might be able to regenerate from serious injuries in a matter of minutes instead of hours or days. Moreover, his ability to influence the weather around him could also increase. He could create powerful storms or clear skies depending on his needs in battle.
Naruto could gain enhanced sensory abilities. Kurama has a certain awareness of its surroundings, and with both halves, Naruto would be able to sense things from much greater distances. He might also develop a new form of Rasengan that incorporates both the yin and yang aspects of Kurama's chakra, making it even more destructive and versatile. Additionally, he could gain the ability to communicate with other tailed beasts more effectively, as he now has a more complete connection to Kurama.
Well, if Naruto had both halves of Kurama, he would be incredibly powerful. His chakra reserves would likely be off the charts. He could perform more powerful jutsus with ease and might even be able to take on stronger opponents single - handedly. For example, in battles against the Akatsuki, he could have ended the fights much quicker.
Naruto could develop the ability to better understand and manipulate the chakra of others. His maturity might give him the wisdom to see the flow of chakra in different ways. Additionally, he may gain the ability to quickly analyze battle situations and come up with more creative solutions due to his increased mental maturity.
He might gain the ability to see chakra in a more detailed way. Since the Rinnegan is known for its enhanced visual perception of chakra, Naruto could use this to his advantage when dealing with Kurama's chakra. He could also potentially use the Rinnegan's power to enter Kurama's mindscape in a new way, maybe with more control and understanding. Another possible ability is to transfer Kurama's chakra to others in a more efficient and controlled manner using the powers of the Rinnegan.
In terms of physical training, Naruto would need to train his body to withstand the greater power of both Kurama halves. He could do more strenuous exercises like lifting extremely heavy weights or running at high speeds for long distances while in a Kurama - enhanced state. Also, his mental training would be crucial. He would need to be mentally strong to handle the influence of both Kurama halves on his mind and to be able to access their power when needed without losing control.
One new ability could be Force jump. Naruto could use the Force to propel himself into the air much higher and farther than his normal jumps. Another would be Force sense, which would let him detect hidden enemies or traps more easily. He could also use the Force to influence the minds of his opponents on a minor level, like creating distractions or making them hesitate during a fight.
Well, having both halves of Kurama would significantly boost Naruto's power level. Kurama is already an extremely powerful tailed beast, and with the complete form, Naruto would have access to even more chakra. His attacks would be more powerful, and he could probably use some new and enhanced forms of his existing jutsu. For example, his Rasengan might become much larger and more destructive.
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 might gain the ability to cut through any chakra - based defenses. Since the Master Sword is often depicted as a very powerful weapon, it could enhance Naruto's combat capabilities against tough opponents.
He might gain enhanced speed and strength. The fox is known for its agility and power, so when summoned, it could transfer some of those traits to Naruto. For example, he could run faster than he already can and deliver more powerful punches.