Who could be the main antagonist in 'naruto destroys konoha crossover fanfiction' if not Naruto himself?

It could be Sasuke. If he were to turn to the dark side in the fanfiction, his Rinnegan powers could be used to destroy Konoha. He has the potential to be extremely powerful and if he has some sort of vendetta or is influenced by some dark force, he might take his anger out on the village.

Madara Uchiha could also be a possible antagonist in this scenario. Even if he is dead in the original story, in a fanfiction, his lingering influence or a resurrected form could manipulate Naruto. Madara was always against Konoha's ideals to some extent and might use Naruto as a tool to destroy what he hated.

The hidden enemies within Konoha who oppose Naruto's ideas of peace and unity could be antagonists. They might spread false rumors about Naruto, turning the villagers against him. This growing animosity between Naruto and the village could result in him lashing out at Konoha, making those who spread the rumors antagonists in the fanfic.

It could be a new character that we haven't seen in the original Naruto series. This character might be jealous of Naruto's power and wants to see him destroy his own world so that he can take over the chaos that follows.

It could be a corrupt elder in Konoha. They might be power - hungry and see Naruto as a threat to their control. So they manipulate the situation to make Naruto the enemy.

Perhaps in this fanfiction, there is a dark prophecy that Naruto misinterprets as Konoha being the source of all evil in the ninja world. So, in his attempt to 'save' the world, he decides to destroy Konoha. Also, it could be that an evil entity has merged with Naruto, and the combined power has a grudge against Konoha for some past event.

It could be a long - lost relative of one of the old villains like Orochimaru. Maybe this person has been in hiding, training and growing in power, and now wants to take revenge on Konoha for what happened to their family member.

Maybe the main antagonist is a powerful figure within Konoha who doesn't want Naruto to leave and become an independent force. He secretly sends assassins after Naruto. When Temari gets involved, this figure also targets her. His actions are driven by his thirst for power and fear of Naruto's potential outside of Konoha's control.

Perhaps it's an old enemy who has somehow managed to come back stronger. Maybe someone from Orochimaru's old experiments that went wrong, but instead of dying, they gained some dark and powerful abilities. They see Naruto's return as a threat to their plans of world domination, so they target Konoha first. They might be able to control dark chakra in a way that no one has seen before, and use it to create chaos and destruction. They could also have some minions who are equally as powerful and loyal to them, making them a formidable foe for Naruto and Konoha.

The elders of Konoha could be the main antagonists. They might be the ones who have been neglecting Naruto all along, and when he leaves, they see him as a threat to Konoha's stability.