In the 'naruto can use the force' fanfiction, Naruto could gain the power of force - vision. This would allow him to see things that are normally hidden, like secret passages or enemies using camouflage techniques. He could also develop the ability to manipulate the elements in a new way. For example, instead of just using wind - style jutsu, he could use the force to control the air currents more precisely. He might be able to create small tornadoes or gentle breezes at will, adding a new level of finesse to his elemental manipulation skills.
Naruto could gain the ability to communicate telepathically using the force. This would be useful in coordinating with his teammates during a battle or getting information from afar. He might also be able to levitate himself or objects of significant size, which would be a great advantage in both combat and non - combat situations. For instance, he could levitate boulders to use as cover or to attack his enemies. Also, he could potentially use the force to heal himself or others to some extent, a very different kind of power compared to his normal ninja healing techniques.
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.
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.
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.
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 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.
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.
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.
Naruto could gain the ability to fly on a magical creature. Since Fairy Tail has many flying creatures, he could bond with one and use it to travel. This would be a new form of mobility for him compared to just running or using his ninja skills for transportation. Also, he could learn some kind of transformation magic that is different from his own shadow clone or Sage Mode transformations.
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.
He could gain the ability to use a sword more effectively. Cloud is a master swordsman, and Naruto, under his tutelage, might learn some amazing sword - fighting techniques. Also, Cloud has some superhuman strength and speed, and Naruto could potentially inherit or be trained to have similar enhanced physical abilities.