A group of power - hungry warlords could be the main antagonists. These warlords might have emerged during the post - war period in the parallel world. They see the chaos as an opportunity to seize control over various regions. They don't care about the traditional ninja village system and are willing to use any means, including dark jutsu and enslaving other ninjas, to achieve their goals. Naruto would have to stand up against them to protect the freedom and peace of the ninja world.
One possible plot could be that in the parallel world, Naruto has to face new threats that emerged due to the chaos of the war. Maybe the villages that were once allies now have different power dynamics. For example, Konoha might have to deal with a new group of rogue ninjas who are using the post - war confusion to their advantage. Naruto, as the hero, has to use his skills and wisdom to unite the villages again and stop this new menace.
It could be some rogue ninjas who were against the peace treaties after the war. They might form a group and try to disrupt the newly - established peace in the ninja world.
It could be a group of corrupt business people. They use their wealth and influence to manipulate the city's economy and politics for their own gain. Naruto, with his sense of justice, would oppose them. For instance, they might be trying to close down a community center that helps underprivileged kids, and Naruto steps in to stop them.
In a more futuristic world, a corrupt corporate leader could be the bad guy. He wants to use Naruto's abilities for his own profit, like making Naruto fight in illegal gladiator - like battles for entertainment. If Naruto refuses, he threatens to harm the people Naruto has grown to care about in this new world.
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.
There could be a new group of villains who emerged from the shadows. They might have been observing the war and learned from the mistakes of previous antagonists. They could be more powerful and cunning, perhaps using new forms of jutsu or technology that were developed during the war. Maybe they are after some ancient artifacts or secrets that were unearthed during the Fourth Great Ninja War.
It could be some of the traditional power - hungry ninja clans who oppose Naruto's new world order. They might see his attempts at global control as a threat to their own interests and try to undermine him.
The Sound Ninjas could be great antagonists. They could use their own unique parkour - like skills to try and stop Naruto. They might be chasing him through the forest, and Naruto has to use his parkour skills to outmaneuver them.
Maybe some corrupt officials within the prison system itself. They oppose Naruto's more humane and reform - focused approach to prison management. They might try to undermine him at every turn, for example, by cutting off resources or spreading false rumors about him among the prisoners.
Maybe a group of dark - type Pokémon that have banded together and are trying to overthrow Arceus. They view Naruto as an easy target at first, but quickly realize he is a formidable opponent with his ninja skills and new Pokémon - related powers. They would constantly try to undermine Naruto and his efforts to protect the Pokémon world.