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.
In such a fanfiction, a whip made of chakra - resistant material could be made. This whip could be used to disarm opponents or even bind them. The creator could also come up with a gauntlet that has the ability to absorb and redirect an opponent's chakra attacks. It would work by having special seals on the gauntlet that trap the incoming chakra and then send it back towards the attacker.
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.
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.
In some Harry Potter fanfictions, the weaponsmith might create a wand with a core made of a rare magical creature's hair, like a phoenix feather from a unique phoenix variant. This could result in a wand with extremely powerful and unpredictable magic.
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.
In some Wave - related fanfictions, Naruto might find a unique sword. It could be a sword with special powers like being able to cut through almost anything. Maybe it has some sort of chakra - enhancing property.
I'm not sure who specifically created it. There are so many Naruto fans out there creating fanfiction, and without more context, it's difficult to determine the creator.