One possible main antagonist could be an ancient evil ninja who was sealed away long ago and is now awakened by Naruto's new - found power. This antagonist might see Naruto as a threat to his plans of world domination and tries to stop him at every turn.
Perhaps a group of rogue ninjas who are jealous of Naruto's god - like status as the first male ninja with such powers. They form an alliance to try and take down Naruto and steal his powers for themselves. They could be led by a powerful and cunning ninja who has a vendetta against Naruto's village.
The Leaf Village authorities could be the main antagonists. Since Naruto is now considered a rogue, they would be the ones trying to hunt him down. They might see him as a threat to the village's stability and security.
In this fanfiction, Naruto could be given god - like speed, strength, and intelligence. Since he is the first male ninja with these powers, he decides to rewrite the rules of ninjutsu. He might start training other ninjas in a new way that focuses on inner power rather than just physical techniques. This could lead to a revolution in the ninja world where Naruto is seen as a pioneer and a hero.
Perhaps there are dark forces from another dimension. These forces might be attracted to Naruto's power and want to either steal it or destroy him to prevent him from using it against them. They could be powerful demons or sorcerers with their own motives.
Another possibility is that the main antagonists could be the leaders of the other ninja villages. They might view Naruto's godlike and rogue status as a danger to the balance of power among the villages. So, they could form an alliance against Naruto, leading to a lot of political intrigue and conflict in the story.
A group of female ninjas who oppose Naruto's presence in their world could be antagonists. They might believe that his arrival will disrupt their way of life and power structures. For example, a powerful all - female clan that has long held sway in the ninja world might see Naruto as a threat to their dominance.
Obviously, the first male ninja would be the main character. But there could also be his mentor, someone who guides him in his ninja training. Maybe an old and wise ninja who has a lot of knowledge about different jutsus.
It could be his own family members who abandoned him. They might come back as antagonists, trying to stop Naruto from reaching his full potential or causing trouble for him out of envy or regret. Maybe they have joined a dark force and are now working against him.
In this fanfiction, the main antagonists might be a group of dark chakra - users. They are jealous of Naruto's godlike powers and want to take over the empire for their own evil purposes. They could be using dark magic to corrupt some of the people in the empire, turning them against Naruto. There might also be some power - hungry politicians within the empire who are not satisfied with Naruto's leadership and want to seize power for themselves. They would plot behind the scenes to bring down Naruto and take over the reins of the empire.
Maybe it could be other ninja clans who are jealous of Naruto's newfound sword bloodline. They might see it as a threat to their own power and status in the ninja world.
Well, in this fanfiction, the Akatsuki could be the main antagonists. They would view Naruto's godlike powers as a major threat to their goals. Since Naruto has been trained by Shendu, his abilities would be unpredictable and extremely powerful. They might band together to try and take Naruto down. Additionally, there could be some ancient demons or spirits that are awakened by Naruto's new powers and they see him as an intruder in their realm, so they become antagonists as well. They would use their own dark magic and powers to oppose Naruto.