One possible new ability is the power of invisibility. Wraiths are sometimes associated with being unseen. Naruto could use this to spy on his enemies or surprise them during battles. He could also use it to play pranks on his friends in a more light - hearted way.
Naruto might gain the power of draining the life force of his enemies. This is a rather dark ability but fits with the wraith theme. However, he would likely struggle with using such a power as it goes against his nature. He would have to find a way to either control it or transform it into a more positive form of energy.
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.
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 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.
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 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.
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.
He might gain enhanced physical strength. The devil gene could give him a boost in his taijutsu skills, allowing him to overpower opponents more easily.
Well, Naruto could gain the ability to heal in a more advanced way. Just as the avatar can sometimes use their connection to the elements to heal, Naruto might be able to do the same with his chakra. He could also have the power to merge with the natural world around him, similar to how the avatar can connect with nature. This would give him an edge in stealth and surprise attacks. Plus, he could develop a new form of sensing, being able to detect not just chakra but also the energy of the elements around him.