Who could be the main antagonists in a 'naruto leader of sound 4 fanfic'?

It could be Orochimaru. Since he had a connection to the Sound 5 in the original Naruto series, he might not be happy with Naruto leading them and try to undermine his leadership.

It could be a powerful warlord who sees Naruto as a threat to his control over the western lands. This warlord might have a large army and be used to ruling with an iron fist.

Well, it could be about Naruto somehow becoming the leader of the Sound 4 and leading them in a new direction. Maybe he uses his own ninja way to reform them, like teaching them about loyalty and friendship instead of just following Orochimaru's dark path.

In a 'naruto leader of the sound 5 fanfic', the plot could involve Naruto somehow taking over the leadership of the Sound 5. Maybe he has a mission where he needs to infiltrate the Sound 5 and ends up being in a position to lead them. He could use his unique ninja way to reform them and turn them from their evil ways.

The Akatsuki could still be a major antagonist. Even if Naruto is emperor, they might oppose his rule as it goes against their own goals of chaos and obtaining the tailed beasts.

One possible antagonist could be a jealous noble from Naruto's own kingdom who feels that Naruto doesn't deserve the prince title. This person might try to undermine Naruto at every turn, spreading false rumors about him or trying to sabotage his diplomatic efforts.

Another possible antagonist could be a fellow inmate who has a personal vendetta against Naruto. Maybe this inmate was once on the wrong side of Naruto's actions outside the prison and now sees this as an opportunity for revenge. He could try to undermine Naruto at every turn, from spreading false rumors about him to physically attacking him when the guards aren't looking.

Another option could be Orochimaru. He has his own motives and is always looking for power. He could be the head of a powerful gang in the criminal underworld of the Naruto world. He would constantly be trying to capture Naruto or his friends to use them for his experiments or to gain more power over the ninja world.

The Akatsuki could still be the main antagonists. They might be interested in Naruto's tails for their own dark purposes, like using their power to create a super - weapon or gain control over the ninja world. Another option could be a secret group of rogue ninjas who have a vendetta against the Uzumaki clan and see Naruto's tails as a symbol of their power that they want to destroy.

One potential antagonist could be a new and mysterious organization that is similar to Akatsuki but with different motives. They might be interested in using Daisuke to open a portal to a different dimension or something like that. They would be constantly trying to kidnap Daisuke and force him to cooperate. Also, Orochimaru or his remaining followers could be antagonists. Even though Orochimaru has changed somewhat in the series, there could still be some of his followers who are more radical and want to use Daisuke for their dark experiments, believing that he has some special chakra or ability that could help them achieve their twisted goals.