Kisame Hoshigaki is often associated with it. Given his shark - like appearance and his use of the Samehada, which is a large and unique sword, he could be easily incorporated into fanfiction involving the 8 Sword Style. His brute strength and combat skills would make for an interesting take on how he might adapt to or already be related to the 8 Sword Style.
Some original characters created by fanfiction authors can also be popular in this regard. These are often self - inserted or entirely new characters designed specifically to showcase the 8 Sword Style. They might have unique backstories that explain their connection to the style, such as being descendants of an ancient sword - smithing clan that had a secret knowledge of the 8 Sword Style.
Naruto himself can be a central character in such fanfictions. Given his own vast chakra reserves and his ability to learn new techniques quickly, he could be the one to unlock the true potential of the chakra chains. He might use them in a battle against a powerful new enemy, perhaps one that is immune to his regular jutsu but vulnerable to the unique properties of the chakra chains.
Some fanfictions might link the swords to the Akatsuki members. They are powerful and their motives could be tied to the acquisition and use of these powerful elemental swords. For example, Pain might be interested in the swords to further his goal of bringing pain and chaos. His Rinnegan could potentially have some unique interactions with the powers of the swords.
There could also be a mysterious and powerful swordsman character who is a master of the 9 sword style. They play a crucial role in the fanfiction, perhaps as a mentor to the other characters or as a key figure in a major conflict that involves the 9 sword style.
Sasuke is often involved. His natural affinity for sword - play and his powerful abilities like the Sharingan make him a prime candidate for fusion - related stories. Fans like to imagine him fusing his sword skills with other strong characters.
Often, Naruto himself might be associated as he is the main character of the original series. Writers may give him the devil bloodline to explore how it changes his character and abilities.
Naruto himself could be one. Imagine him getting a hold of a legendary weapon that enhances his already powerful Rasengan. Sasuke is also a likely candidate as his quest for power could be intertwined with a legendary weapon.
Naruto himself is often associated with it. Since he is the main character of the series, many fanfictions explore his potential with the Lightning Armor. He might learn to use it in unique ways, like combining it with his Rasengan.
Naruto himself could be one of the main characters associated with it. Since he has such iconic spiky hair, it's easy to imagine him developing some unique hair jutsu. Sakura might also be involved, as her long hair could be used in interesting ways in fanfiction. And Sasuke, his cool and somewhat long hair could also be a factor in hair jutsu - related stories.
Sasuke might also be a main character in such fanfiction. His Sharingan and his own strong chakra could potentially be used in relation to the chakra arrow. He could use his Sharingan to predict the path of the chakra arrow or enhance its power.
Sasuke is often a character associated with black chakra in fanfiction. Given his natural inclination towards power and his dark past, it's easy to imagine him being connected to such a powerful and mysterious form of chakra.