Naruto could also gain enhanced stealth abilities. Haku was known for being able to move stealthily and blend in with his surroundings. With Haku's bloodline, Naruto might be able to use this to his advantage in espionage or surprise attacks. He could even use the ice - based abilities in combination with stealth, for example, creating ice mirrors in hidden locations to ambush his enemies.
He might gain the ability to manipulate ice like Haku. This could be a very useful addition to his existing skill set, especially in battles against fire - type opponents. He could create ice clones instead of the regular shadow clones, which would be more durable in certain situations.
It could also be a result of a unique encounter with a powerful entity. For instance, if Naruto entered a mysterious realm where the essence of Haku's bloodline was stored, and some sort of transference occurred, perhaps due to Naruto's own unique chakra nature. This could lead to him obtaining Haku's bloodline.
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.
In this fanfiction, Naruto would gain the ability to manipulate the elements in new ways. Each tailed beast is associated with a different element or combination of elements. By having all of them, he could create complex elemental attacks that are not possible before. For instance, he could combine the fire of one tailed beast with the water of another to create steam - based attacks. His healing factor might also be enhanced as some tailed beasts possess regenerative abilities. This would make him even more difficult to defeat in combat.
He would likely gain enhanced cutting and slashing abilities. Each of the seven swords has its own unique properties, so Naruto could use them in combination with his existing ninjutsu. For example, he could use the swords to channel his chakra more effectively, increasing the power of his attacks.
He might gain the ability to control wood - style jutsu more effectively. Since Hashirama was known for his powerful wood - style, Naruto could use it to create huge forests for defense or to trap enemies. For instance, he could grow trees instantly to block incoming attacks.
He might gain better chakra control. Kakashi could teach Naruto how to precisely manage his chakra, allowing him to perform jutsus more efficiently and for longer periods. For example, Naruto could use his Shadow Clone Jutsu without exhausting his chakra so quickly.
Naruto might gain superhuman strength like Kratos. He could easily break through solid rock or lift extremely heavy objects. His speed could also increase, allowing him to move so fast that enemies can barely see him. Maybe he could also have the ability to summon the blades of chaos, which he could use in combat in a unique way, like combining them with his kunai.
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 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.