Characters like Gaara may also appear. He could be an ally king to Naruto, and together they form a powerful alliance against common enemies. The Akatsuki members might be the antagonists in some fanfictions, trying to overthrow Naruto's kingdom or steal valuable resources from it.
The main character is Naruto, no doubt. But other characters from the Naruto universe can also be main players in these fanfictions. For example, Jiraiya could make an appearance. He might have known about Naruto's potential as the 'King of Nature' all along and left some clues or teachings for Naruto to discover. And then there are the various tailed beasts which could have a special connection to Naruto as the 'King of Nature'.
Often, you'll see Hinata as part of the harem. Her shy nature contrasts with Naruto's more bold Mokuton - using self. Sakura might also be there, adding an interesting dynamic as she has her own history with Naruto. And then there could be some original characters created just for the fanfiction to add more flavor to the harem.
Hinata is also often paired with Naruto. In a fanfiction, Hinata might notice Naruto flinching and use her gentle and understanding nature to comfort him. She could be the one to figure out what is wrong and support Naruto through his difficult time, which would further develop their relationship in a sweet and tender way.
Well, Naruto himself is obviously a central character. Then there are often female characters like Sakura, Hinata, and Ino. Sakura might be written as more aggressive in her pursuit of Naruto in the harem scenario. Hinata could be the shy but very loyal one, and Ino might bring a bit of sass and competition to the group.
Obviously Naruto himself is the most common. His friends like Sasuke and Sakura also often appear. Kakashi - sensei might show up too, perhaps to give Naruto some sage advice during his bath time. And Jiraiya could be there as well, since he was Naruto's mentor and had a close relationship with him.
Sakura could be a common supporting character. She might be jealous of Hinata's relationship with Naruto at first, but then comes to accept it and even helps them in the game - related adventures. Shikamaru could also be there. His intelligence would be useful in devising game strategies for Naruto and Hinata. Kiba and Akamaru might be their opponents in some game battles, adding an element of friendly rivalry.
In these fanfictions, a very common element is Naruto's enhanced strength and abilities. He may be able to traverse between the living world and the afterlife at will. His moral code might also be put to the test as he rules over hell. There could be a lot of focus on his interactions with the denizens of hell, be they former foes or new characters created specifically for the fanfiction. Moreover, there may be a backstory about how he came to be the 'godlike naruto king of hell', which often involves some sort of epic journey or transformation.
Love and loyalty are common themes. Naruto as a king often has to face many challenges, and Hinata's loyalty to him and their growing love is a central focus. For example, in many fanfictions, Hinata stands by Naruto through political unrest.
Hinata is often a common character. Given her long - standing feelings for Naruto in the original series, it's easy to incorporate her into an Anbu Harem scenario. Sakura can also be a part of it. She's a strong female ninja, and her relationship with Naruto in the canon can be tweaked in the fanfiction to fit the harem concept. Ino is another possibility. She has her own charm and skills, and in a fanfiction setting, she could be attracted to Naruto within the Anbu context. Also, some original female characters created specifically for the fanfiction might be included to add more variety to the harem.
Kakashi is another character that might show up frequently. He could be Naruto's mentor in understanding the sword's powers or the mysteries behind it. Jiraiya might also be present in some fanfictions. He could have some connection to the sword from his past adventures and pass on some important information to Naruto. Additionally, villains like Orochimaru might be interested in the sword and try to steal it from Naruto, which makes them common characters in these fanfictions.