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.
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.
It could be a dark wizard who has found a way to control others from the shadows. Maybe someone who was once defeated but has now returned with this new and terrifying power.
It could be an unknown dark wizard who has been lurking in the shadows all this time. Maybe he was once a student at Hogwarts who was shunned and now wants revenge by controlling everyone.
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.
There's a possibility that the Dark Puppet Master is a new character entirely, created specifically for the fanfic. This character could be from a small, unknown village that was destroyed by the larger ninja villages in a past war. Driven by revenge, they developed their puppet - controlling skills in secret and now emerge as a powerful and menacing figure in the Naruto fanfic.
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.
It could be a rogue ninja who was once a student of the Hiraishin master but turned evil. They might have a twisted view of the technique and use it for their own selfish and harmful purposes, like stealing important artifacts from different villages.
One potential antagonist could be a rogue ninja who also specializes in bojutsu. He might be jealous of the main character's skills and tries to undermine him at every turn. Another option is a powerful villain from the Naruto universe who sees the bojutsu master as a threat to his plans.
A rogue ninja who has mastered all the dark aspects of the elements could be a great antagonist. This ninja could use their powers to create disasters, like summoning tsunamis with water element or causing volcanic eruptions with fire element. They might have a vendetta against the Hidden Leaf Village and see Naruto as a threat to their plans because of his growing elemental powers.
Danzo could be an interesting antagonist. He's a very secretive and power - hungry character. He might see a blade master as a loose end or a potential weapon that he wants to either eliminate or use for his own political gain in the Hidden Leaf Village. His underhanded methods would create a lot of conflict with a blade master who likely has a strong sense of honor.