Alina is also frequently involved. Her connection to the Darkling in the original work makes her a natural addition in many fanfictions. Their complex relationship can be further explored or even rewritten in different ways in fanfiction.
Then there are other Grisha characters. They might play different roles depending on the plot of the fanfiction. For example, some might be loyal allies of the Darkling, while others might oppose him. Their powers and personalities add depth and variety to the stories.
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.
Obviously Naruto himself is a main character. He is the one with the pacemaker so he is central to the story. Sasuke might also be involved. He could be initially skeptical of Naruto's new situation with the pacemaker but then come around to help. Sakura too, as a medical ninja, she could play a crucial role in understanding and perhaps even trying to modify the pacemaker.
Naruto is almost always a main character in 'naruto dice fanfiction' as the story is based on the Naruto universe. His friends like Sasuke and Sakura also often appear. Sasuke's cool and brooding nature can add an interesting dynamic when combined with Naruto's more upbeat and impulsive personality in stories related to the dice.
Bella and Edward are often main characters in such fanfiction. Since their relationship is central in the original Twilight series, in fanfiction about sacrifices, they could be the ones making sacrifices for each other. For example, Edward might sacrifice his vampiric nature to give Bella a more 'normal' life if she so desires.
Naruto himself is obviously a main character in such fanfictions. His growth in intelligence is usually the central focus. Sasuke can also be involved as Naruto's rival or ally in situations where intelligence plays a crucial role. Sakura, with her own intellectual capabilities in medical ninjutsu and general knowledge, often appears as well.
Sasuke is also commonly involved. His own journey of self - discovery and redemption is a rich area for fanfiction writers. His complex past and his actions that have caused harm in the Naruto world make his redemption arc an interesting topic to explore, especially in relation to how he reconciles with Naruto and the rest of the village.
Sakura could also be a main character in such fanfiction. Given her intelligence and medical skills, she might be working in the lab, conducting research on new ways to heal ninja injuries or even enhance their physical abilities through some sort of medical - ninja technology combination.
Obviously Naruto himself is the central character. Sakura might also be involved as she could be one of the few in the village who believes in Naruto's innocence and tries to help him from afar.