A possible weapon for Naruto could be a sword. In Soul Eater, swords are common weapons. Naruto's sword could have the ability to cut through not just physical objects but also spiritual ones. It could be infused with his chakra and have markings on it that represent his ninja heritage, like the Uzumaki symbol.
Naruto might be a staff - type weapon. He could use it for both close - range combat and to channel his chakra or soul power. The staff could have different forms, like it could extend or transform into other shapes depending on the situation, similar to how he can transform his Rasengan.
Naruto could be seen as a weapon that has the spirit of a ninja within it. His chakra system might be reworked to be more like the soul wavelength in Soul Eater. His Nine - Tailed Fox power could be a hidden, extremely powerful aspect of the weapon. He would likely have a strong sense of justice still, but it would be expressed in the context of the Soul Eater universe, like fighting to protect souls instead of the Hidden Leaf Village.
It could be a sword. In many fanfictions, swords are common powerful weapons. Since the Shinigami is often associated with death and power, a sword with special abilities like being able to cut through spiritual barriers or absorb chakra could be a likely weapon for Naruto to obtain.
Perhaps it's a unique staff. A staff could have different uses, like being a conduit for chakra. It could also have hidden compartments or be made from a rare material that gives Naruto an edge in battles. For example, it might be made from a metal that can absorb chakra attacks and then redirect them.
Well, it could be a sword with the power to cut through any jutsu. Maybe it has some special markings that only Naruto can understand. It might also be a staff that can control the elements in a unique way, giving Naruto an edge in battles.
Well, perhaps Harry could be a weapon that has the power of his magic from the Potter world. He might be used by a Soul Eater character to fight against evil souls. Maybe his wand could transform into a more weapon - like form in the Soul Eater world.
It could be a super - charged kunai. Maybe it has some kind of special chakra - enhancing ability that makes Naruto's attacks much more powerful than normal.
It could be a sword that can cut through any substance, like the Susanoo easily. Just imagine Naruto swinging it and slicing through powerful jutsu defenses as if they were paper.
Perhaps in this fanfiction, Naruto discovers that he has some unique weapon - like abilities that are different from his normal jutsu. It could lead to a whole new adventure where he has to learn to control this 'weapon' aspect of himself while still being true to his friends and the village.
One possible perfect weapon in Naruto fanfiction could be a sword that can cut through any chakra - based defense. It would give the wielder a huge advantage in battles against powerful ninjas.
In a fanfiction where Black Star becomes a weapon, his design as a weapon would probably be very unique. Given his love for being flashy and his ninja - like style, he could be a weapon that has a lot of sharp edges and a sleek, black design. Maybe he'd be a sword with some sort of special ability related to his ninja skills, like being able to disappear and reappear during combat, or having the ability to cut through dimensions.