In some fanfictions, there's an original character who is a master of both ice and lightning techniques. This character has a mysterious past and often clashes with the Ice Dragon Slayer at first but later becomes an ally. They bring a new dynamic to the story as they can combine their powers in unexpected ways. Another interesting character is a healer who has a special connection to the Ice Dragon Slayer. They can heal the slayer's wounds in a way that also enhances their ice powers, which is really cool. There's also a character who is a rogue ninja that has been studying the Ice Dragon Slayer from afar and has some devious plans related to their powers.
One interesting original character could be a young ninja who is in awe of the Black Fire Dragon Slayer. This character might start off as a weakling but is inspired by the slayer to train harder and develop their own unique abilities. Another could be a mysterious old man who has knowledge about the origin of the Black Fire Dragon Slayer's powers and guides them on their journey. And there could be a female ninja who has a rivalry with the slayer at first but later becomes their ally and love interest.
There's this one character named Kira. He's a self - taught Sky God Slayer who has a really unique fighting style. He combines Naruto - style ninjutsu with his Sky God Slayer magic in unexpected ways. Another interesting character is Luna. She has the ability to control the weather on a small scale using her Sky God Slayer powers, which makes her a force to be reckoned with in battles.
One popular plotline could be the Ice Dragon Slayer character from a different world ending up in the Naruto universe. They might have to adapt to the ninja world while also using their ice dragon slaying abilities in unique ways, like fighting the Akatsuki. Another could be the Ice Dragon Slayer training Naruto or some of the other ninja in ice - based techniques, which would be a new and interesting addition to the existing jutsu in the Naruto world. And sometimes, there's a plotline where the Ice Dragon Slayer has a hidden past related to an ancient clan in the Naruto universe that gives them special powers or a mission to fulfill.
Sasuke would be really interesting. He already has a dark and brooding nature. Adding Ice Devil Slayer powers would enhance his cool and aloof demeanor. He could use the ice powers in combination with his Sharingan and fire - based jutsu in really unique ways. For example, he could freeze the water created by a water - style jutsu and then shatter it with his ice powers.
Obviously, Naruto himself is very popular as he is the main character of the original Naruto series. The White Dragon Slayer is also a central figure in these fanfictions. Sakura might also be a popular character as she could interact with the new elements brought in by the White Dragon Slayer. Kakashi could be involved too, perhaps mentoring the White Dragon Slayer in some ninja skills.
Sasuke could be really interesting in this type of fanfiction. Imagine him adapting his Sharingan abilities to work with ice - style jutsu, creating some really cool and powerful combinations.
Obviously Naruto is one of the main characters. And of course, the Ice God Slayer would be a main character as well. There might also be characters like Sasuke who could get involved, either as an ally or an antagonist depending on the plot.
It's hard to say without reading it, but it could be the ice dragon slayer themselves. Maybe there's also a wise mentor figure who guides the slayer.
Gray Fullbuster is a great character to write about. He already has ice - making abilities, so as an Ice Devil Slayer in fanfiction, he could have some really cool power - up scenarios. His brooding nature also gives a lot of room for character development. You could explore his past more deeply and how it relates to his newfound Devil Slayer powers.
In Dark Naruto Mokuton fanfiction, one popular type of original character is the healer. Since Naruto's dark side and Mokuton powers could potentially cause harm to himself or others, a healer character is created to keep things in balance. They might have unique healing abilities that work specifically with chakra imbalances caused by the dark side and Mokuton. Also, there are often original antagonists who are specifically after Naruto's Mokuton power because of its rarity and strength when combined with his dark side.