He could become a weapons master through some kind of special power-up. For example, a new chakra form that gives him an affinity for weapons. He might be able to infuse his chakra into weapons, making them more powerful. And Naruto is known for his hard work, so he'd surely spend countless hours training with various weapons, from swords to shurikens, until he masters them.
One way is to base the weapons on existing ninja tools in the Naruto universe. For example, you could create a modified version of the kunai, like a kunai with a hidden blade that can extend for surprise attacks. Another idea is to draw inspiration from nature. Maybe a weapon made from a special tree in the Hidden Leaf Village that has unique properties, such as being able to absorb chakra.
Some fanfictions describe that Naruto chakra weapons are created by skilled blacksmiths who have a basic understanding of chakra. They infuse chakra - conductive materials with the user's chakra during the forging process.
Let's say he gets a weapon that can transform. For example, it can change from a small dagger to a large spear. This would make his combat style more versatile. He could start a fight with the dagger form for quick, sneaky attacks, and then transform it into a spear when he needs more power and reach. This new weapon would force him to learn new fighting techniques and adapt his style to make the best use of its abilities.
The katana would be really interesting. A katana in Naruto's hands could be a powerful weapon. He could use his speed and strength to make swift and deadly strikes. Also, a chained weapon like a kusarigama. He could swing it around with great force and use his ninja skills to control its movement in battles, entangling his enemies.
Naruto's combat style becomes more self - reliant. Instead of relying solely on the weapons provided by the village, he can customize his arsenal according to his strengths. If he is good at close - range combat but lacks in long - range attacks, he can create a weapon that bridges that gap, like a projectile weapon with a long - range homing ability.
He might use them in combat against powerful foes in the Naruto world. For example, if Yang's weapon is a special sword, Naruto could incorporate his ninja skills like chakra control and acrobatic movements to wield it effectively in battles against Akatsuki members.
In this fanfiction, Naruto might also create a shield. This shield could be made from a combination of rare materials he discovers during his adventures. It has the ability to not only block physical attacks but also absorb and redirect chakra - based attacks back at the enemy.
Well, it could work if there's some sort of crossover magic. Maybe Naruto is transported to the RWBY universe and he somehow gets his hands on Yang's weapons. He might use his ninja skills in combination with the power of those weapons in a really unique way.