Who could be the main antagonist in a 'Naruto banished Temari' fanfiction?

A power - hungry politician from one of their villages could be the main antagonist. This person might see Naruto and Temari's relationship (if that's part of the reason they are hiding) as a threat to his plans for power. He wants to use their situation to his advantage, either by forcing them to do his bidding or by getting rid of them altogether.

Maybe the main antagonist is a group within Naruto's own village. The elders or some of the more conservative clans who banished Naruto in the first place. They fear that if Naruto returns as the banished emperor, he will change the power structure that they have been maintaining for so long. So they do everything they can to stop him from coming back, even if it means allying with outside forces.

A powerful Hollow could be the main antagonist. This Hollow could sense Naruto's unique energy and see him as a threat to its plans of taking over Karakura. It might constantly target Naruto and his new friends, trying to eliminate them one by one.

It could be a rogue ninja from a neighboring village who wants to obtain Naruto's Rinnegan for himself. This ninja has been secretly observing Naruto and sees the potential of the Rinnegan. He then tries to hunt Naruto down during his banishment to take the power.

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.

The main antagonist could be a powerful demon that has been sealed in the Fairy Tail world for a long time. Naruto's arrival disrupts the seal somehow, and the demon sees Naruto as a key to fully breaking free. The Fairy Tail members and Naruto must put aside their differences and combine their powers to fight this demon.

Perhaps a secret organization within the Hidden Leaf that wants to take over the village. They use Naruto as a scapegoat, getting him banished so they can carry out their evil plans without interference from Naruto. They would be the main antagonists as they are the ones behind the false accusations and the push for his banishment.

Perhaps a group of vampires who are trying to take over the entire Rosario Vampire world and are causing harm to both humans and other supernatural beings. Naruto views their actions as unacceptable and makes it his mission to banish them. They could be very strong and have some special abilities that make them a formidable foe for Naruto.

It could be a powerful pirate crew that doesn't like the idea of an outsider like Naruto coming into their territory. They might see him as a potential rival for treasures or influence, so they try to drive him out or even eliminate him, thus becoming the main antagonists.

It could be a powerful wizard in the new world who sees Naruto as a threat to his rule. Since Naruto has unique powers from his own world, the wizard might want to eliminate him or use his powers for his own evil purposes.