Obviously Naruto himself is often the main character as it's about his muscle growth. Sasuke can also be involved, perhaps as a rival who is both impressed and a bit envious of Naruto's new - found physical power.
Bella herself can also be part of these fanfictions in terms of how she reacts to the muscle growth of the male characters. Her perspective, whether it's admiration, fear, or something else, can add depth to the story. Also, sometimes in unique fanfictions, she might even have some form of power - related muscle growth herself.
Obviously, Naruto is often the main character in 'Naruto hyper muscle fanfic' as the concept revolves around him having hyper muscles. His friends like Sasuke and Sakura are also likely to be involved. Sasuke might be initially jealous of Naruto's new power or might be inspired to train harder. Sakura could be the one to help Naruto understand and control his new strength from a medical ninja's perspective.
Ben Tennyson is almost always the main character in 'ben 10 muscle growth fanfic' since it's based on the Ben 10 series. His transformation and the resulting muscle growth are central to the story. Sometimes, his alien forms might also be involved in a different way because of the muscle growth concept.
Naruto himself is often a central character in 'naruto destruction fanfiction'. Since he is the main protagonist of the original series, fanfiction writers like to put him in situations where he has to deal with destruction. Sasuke is also frequently involved as his rival, and their relationship can be explored in the context of destruction, like if they have to work together to stop a greater threat of destruction.
Well, Naruto is obviously a main character in most of these. But there could also be Sasuke. He might be either an ally or an adversary in relation to the dagger. For example, if the dagger has a power that can either be used for good or evil, Sasuke could be tempted by its darker potential.
Some fanfictions might also include characters like Kakashi in important roles. As Naruto's former teacher, he could be a guiding figure or someone who has to adapt to Naruto's new level of power. He might also be involved in trying to keep Naruto's power in check if it starts to have negative effects on the ninja world.
Naruto himself is often a main character in naruto helmet fanfiction. Since he is the protagonist of the original series, it makes sense that he would be involved with a special helmet in fan - created stories. He could discover the helmet's powers and use them to become even stronger.
Naruto himself is often involved. Since he's the main character of the original series, in fanfiction with loopholes, he might use some loophole to achieve his goal of becoming Hokage faster or getting stronger in a unique way. Sasuke could also be a main character in such fanfictions. He might find a loophole to deal with his quest for revenge or his power - seeking in a different manner.
In many Naruto scream fanfiction, Kakashi Sensei can also play an important role. He might be trying to teach Naruto how to control his scream in a more strategic way, or he could be using Naruto's scream as a signal during a mission. Also, characters like Jiraiya might be involved. Jiraiya could be training Naruto to use his scream as a form of attack or defense, as part of some new and unique jutsu.
Definitely Naruto as the victim of hypothermia. Shikamaru could also be involved. He might be the one strategizing the rescue mission, using his intelligence to figure out where Naruto could be in the cold environment. And Hinata might be there too, her concern for Naruto adding an emotional aspect to the story.