Perhaps Rock Lee. He's always been enthusiastic about Naruto. In the forest, Lee could show his admiration in a more romantic way. They could train together and Lee could help Naruto navigate the dangerous forest, leading to a yaoi - like relationship between them.
It could be Sasuke. Since they have a complex relationship in the original series, in the yaoi fanfiction, their relationship could take a different turn in the Forest of Death. They might have more intimate moments while facing the challenges there.
Well, one possible plot could be Naruto exploring the dangerous parts of the Forest of Death while forming an unexpected bond with another male character. Maybe they start off as rivals but gradually develop a deep emotional connection as they face the perils together.
Kakashi could also be a main character. He has lost many people close to him, like his father, Obito, and Rin. Facing the death goddess, he could be in a moral dilemma. He might be tempted to use her power to change the past, but also realizes the consequences that could come with meddling with death. His internal struggle could be a central part of the fanfiction.
Well, in some fanfictions, Naruto might encounter a mysterious creature in the Forest of Death. This creature could befriend him and teach him some unique skills or give him special powers that are not part of the original Naruto universe. For example, it could teach him how to communicate with animals, which would be really cool and useful in many situations. Also, there could be a situation where Naruto stumbles upon a secret training ground within the forest that was once used by a great ninja from the past. He could then use this training ground to enhance his skills further.
Danzo could be the main villain. He is known for his underhanded tactics and his dislike for Naruto. He might see Naruto as a threat to his power and plan to get rid of him by leaving him in the Forest of Death. Danzo could have manipulated some other characters to make it seem like it was a legitimate mission gone wrong.
In this fanfiction, Naruto could be isolated in the Forest of Death. He has to fend for himself, which means he has to figure out how to get food, water, and shelter all on his own. This experience might make him more self - reliant and independent. He may also develop a different view on the concept of family and friendship since he has been alone for so long.
Well, it could be that Naruto discovers a dark secret about his team or the village during the Forest of Death exercise. His so - called friends then think he's a threat and betray him. He might be left alone to fight against powerful enemies like the Sound Ninja. Naruto, being the determined character he is, would then strive to become stronger and show that he's on the right side. He could start training alone in the forest, learning new jutsus to protect himself and seek revenge if necessary.
Hermione could be one. She might come to the forest to check on Harry and end up staying to study the unique flora and fauna which have magical properties. Another could be Hagrid. He loves all kinds of creatures and the forest is full of them, so he could visit Harry often and bring him supplies.
Naruto is also very popular. His never - give - up attitude and his ability to make unexpected allies are fun to write about in the context of the Forest of Death. He might find unique ways to use his shadow clones or befriend some of the forest creatures in fanfiction.
In the fanfiction, Naruto being abandoned in the Forest of Death could lead to him making unexpected alliances. He could meet some strange creatures that at first seem hostile but end up helping him because they recognize his tenacity. He might also discover some ancient secrets or jutsu hidden in the forest that could change his fate in the ninja world.
Sasuke could be a likely candidate. He's always been somewhat jealous of Naruto's growth and popularity. In the stress of the Forest of Death, he might let that jealousy get the better of him and betray Naruto. Maybe he thinks that by getting rid of Naruto, he can be the only strong one in the team.