Naruto could potentially gain the power of omnipotence. Since the Infinity Stones are extremely powerful in the Marvel universe, in the Naruto fanfiction, they could give Naruto abilities beyond imagination. He might be able to use the Stones together to rewrite the rules of the ninja world. For example, he could make chakra obsolete and introduce a new form of energy using the combined powers of the Stones. Also, he could use the Power Stone to boost the power of his Rasengan to an unimaginable level, capable of destroying entire mountains with a single throw.
He could gain the ability to create large - scale wooden structures, like Hashirama did. For instance, he could build huge wooden golems to fight for him in battles.
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.
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.
One new ability could be enhanced strength. Thor's hammer gives its user great physical strength, and Naruto could use this to his advantage. He could break through stronger defenses more easily, like the fortified hideouts of his enemies. Also, the hammer has the power of returning to its wielder's hand. This would prevent Naruto from losing his weapon during combat, ensuring he always has it at his disposal for the next attack.
Naruto could gain the ability to manipulate light and darkness, which are often associated with Keyblades. This would be a huge change from his normal chakra - based abilities. He could also use the Keyblade to fly, giving him an advantage in both mobility and combat. Another new ability might be the power to heal, as some Keyblades have restorative properties.
Naruto could potentially gain the ability to sense danger more acutely with Akame's sword. In some interpretations, the sword has a certain awareness. This could help Naruto in battles, allowing him to anticipate his opponents' moves better. Also, if the sword has any hidden powers related to Akame's world, Naruto might be able to tap into them. For instance, if there are special enchantments on the sword, he could use them to his advantage, like making himself invisible or resistant to certain types of attacks.
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.
He could gain the ability to see different timelines clearly. The Rinnegan already gives enhanced perception, and with time travel, Naruto could view the consequences of different actions in different timelines. He might also be able to transfer knowledge from one timeline to another. For example, he could learn a powerful jutsu in the past timeline and bring that knowledge back to his original timeline.
He might gain Minato's teleportation jutsu. It was one of Minato's signature moves, and with Minato sealed in him, Naruto could potentially access and learn this powerful technique.
Another ability Naruto could gain is a deeper understanding of genjutsu. Shisui was very proficient in genjutsu, especially with his Sharingan. Naruto, being his brother, could have a natural aptitude for genjutsu. He could learn to break through stronger genjutsu more easily and also use more advanced genjutsu himself. This would be a significant change as Naruto was not originally known for his genjutsu skills, but with this new connection, he could become a more well - rounded ninja.