Naruto could potentially gain the ability to use fox - fire. Since foxes are often associated with fire in mythology, it's possible that through the summoning contract, he could conjure up a special type of fox - inspired fire. This fire could be different from regular ninjutsu fire, perhaps being more difficult to extinguish or having special properties like being able to burn through certain types of defenses more easily.
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.
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 probably gain the ability to phase through objects. Just like wraiths are often depicted as being able to pass through solid things. This would give him an edge in combat and also in sneaking around.
The sword could give Naruto an advantage in close - quarter combat. Since Naruto is mainly known for his long - range attacks and his ability to transform into the Nine - Tails, having Zabuza's sword would force him to improve his close - combat skills. This could lead to him developing new evasion and counter - attack maneuvers, making him a more well - rounded fighter in the fanfiction.
Naruto could have the power of solar - powered regeneration. The sun is often associated with life and renewal. So, if he gets injured, his wounds could heal faster with the energy of the sun. He may also be able to use the sun's energy to enhance his physical strength. He could run faster, jump higher, and hit harder as if he was charged up by the sun's power.
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 could gain the ability to freeze Grimm. In RWBY, silver eyes have the power to harm and sometimes even stop Grimm in their tracks. Naruto's already impressive combat skills combined with this would make him a formidable force. He might also gain enhanced vision, like being able to see in the dark better or detect hidden threats more easily.
Well, in this fanfiction, Naruto might gain some unique powers. Maybe he could communicate with the fox in a special way, like having telepathic conversations. This could lead to him having an edge in battles as he could quickly call upon the fox's strength.
Naruto could gain enhanced senses from the Ghost Rider powers. In the Naruto world, this would help him in detecting hidden enemies or traps more easily. The ability to ride the flaming motorcycle would also be a new skill. This could be used for quick transportation during missions or battles. He could also gain the power of transformation into the Ghost Rider form, which not only gives him a more intimidating look but also access to all the other Ghost Rider abilities. And with the Ghost Rider's connection to the spirit world, Naruto might be able to communicate with spirits in the Naruto universe, which could lead to new plot developments.
He could gain better stealth skills. Hidan is quite good at sneaking around and Naruto might pick up on that. So he could move more quietly and be better at surprise attacks.
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.