I think Sakura could be a great main character too. She has grown into a strong kunoichi. In this fanfiction, she could use her medical skills to study the human puppets, perhaps finding a way to reverse the process of turning a human into a puppet or using her knowledge to heal any damage caused by the puppets' attacks.
Sasuke could be an interesting main character. He has always been on a path of seeking power and revenge. In a fanfiction about human puppets, he might see the potential in using them as a means to achieve his goals, or he could be the one to oppose their creation if he believes it goes against his sense of morality.
Sasuke could be one of the main characters. Given his power and brooding nature, he could be drawn into the world of human puppets and end up in a harem situation. Maybe a puppet master sees his potential and tries to recruit him, and along the way, a group of female characters start to form a harem around him. Another possibility is Naruto himself. His kind heart and strong will could attract a harem while he's exploring the new concept of human puppets. He might try to use the puppets for good, and in the process, gather a group of followers who become part of his harem.
Sasori's apprentice who has gone rogue and wants to create the most powerful human puppets ever. He believes that by using living people as puppets, he can achieve ultimate power. He would be a formidable antagonist as he has Sasori's knowledge and a thirst for more power.
I'm not entirely sure if there is a specific, well - known fanfiction where Naruto is a human puppet. However, given the vastness of the fanfiction community, it's very possible. Fanfictions can range from the most outlandish to the more subtle in their changes to the source material. This idea of Naruto as a human puppet could potentially be used to tell a very dark or a very different kind of story about him.
Obviously Naruto himself would be a main character. He could be the one to face the challenges posed by the puppet sannin. Sasuke could also be involved as he has his own powerful skills that could be used against the puppet - related threats.
Well, it could be a ninja with strong taijutsu skills. Since puppet masters rely on their puppets, a fast and strong taijutsu user could be a big threat. They could quickly close the distance and disable the puppets.
Rock Lee could be an interesting human summon. His extreme dedication to training and unique fighting style would make him a valuable asset in battles. He could be summoned to help Naruto when facing opponents with strong physical abilities.
Often, the main characters include the Puppet King himself. He is usually a complex character with a deep backstory. Then there could be a female ninja who is initially an enemy of the Puppet King but later realizes his true intentions and joins forces with him. Another important character could be an old master who has knowledge about the ancient puppet arts and guides the Puppet King in his journey.
Maybe a kind-hearted storyteller. They have the ability to communicate with the animals in the Lion King world through their stories. The animals are fascinated by the human's tales and the storyteller uses this to bring peace and unity among different animal groups, especially during times of conflict. They could also use their stories to inspire Simba to be a better leader.
The Akatsuki could be the main antagonists. They might see the immortal human as a valuable asset or a threat to their plans. For example, they could want to use the immortal human's unique abilities for their own ends, like using their immortality to perform dangerous and unethical experiments. Or they could view the immortal human as a threat to their goal of world domination, fearing that the immortal human could rally the ninja world against them.
It could be a simple village girl. She might be kind, with a love for nature, which catches Legolas' attention. Maybe she has a special talent like being able to communicate with animals, which is something Legolas admires.