One potential antagonist could be Orochimaru. If Naruto and Temari travel back to a time when Orochimaru was at the height of his power and evil plans, he would surely oppose them. He might see their knowledge of the future as a threat to his schemes to gain immortality and power over the ninja world.
Maybe they travel back to a crucial moment in the Fourth Great Ninja War. With their future knowledge, they are able to prevent certain tragedies from occurring. Naruto could change the course of a battle by warning the Allied Shinobi Forces about an ambush, and Temari could use her strategic mind to better organize the troops.
It could be the same antagonists from the original Naruto series, like Orochimaru or Madara Uchiha. Since Naruto and Temari are time - traveling, they might encounter a younger version of these villains at a time when they were just starting their evil plans. Another possibility is that they create new antagonists by changing the past in some way. For example, if they prevent a certain character from dying, that character could turn out to be an antagonist in the altered timeline.
In some 'naruto and temari time travel fanfiction', a great plotline could be that Naruto and Temari are sent back to a time when the jinchuriki were first created. They might try to find a way to end the cycle of pain that the jinchuriki have to endure. This could involve them having to face powerful ancient shinobi who first came up with the idea of sealing tailed beasts into humans. Also, they could travel to a time when a certain powerful jutsu was first discovered, like the Rasengan or the Wind Scythe. They could either learn the original version of these jutsu or prevent them from being misused in the future.
In 'Naruto x Temari banished' fanfiction, the theme of exile itself is explored in depth. How do they cope with being outcasts? Do they resent their villages or try to find a way back? Also, the theme of cultural exchange can be present. If they travel to different regions, they might encounter new cultures and ways of life, which in turn affects their own beliefs and values. This can be really interesting as it shows how their characters can be molded by new experiences outside of their familiar shinobi world.
In the fanfiction, Naruto might comfort Temari by simply being there for her. He could offer her a friendly shoulder to lean on and listen to her problems without judgment.
Perhaps an ancient evil that was sealed away long ago but is released due to Temari's time - traveling disruptions. This evil entity then starts causing chaos in the past, and Temari is the only one who can stop it with her modern skills and knowledge.
In these fanfictions, the relationship between Naruto and Kushina can be explored in a unique way. Since Naruto has the chance to meet his mother in the past, they could form a strong bond much earlier. It might also affect how Naruto views his own identity, as he gets to know his mother on a deeper level. Maybe he could even learn new jutsu from her that were lost over time.
Well, Naruto x Kushina time travel fanfiction often delves into themes of family and destiny. The idea of Naruto going back in time to meet his mother is quite appealing. It can lead to some emotional moments, such as when Naruto finally gets to experience a mother's love in a more direct way. Writers can also play with the concept of changing the past to shape a better future for the ninja world. There could be epic battles where Naruto and Kushina fight side by side, using their combined powers to face threats that were previously insurmountable.
It could start with mutual respect. Naruto, despite being banished, still has his strong will and Temari would respect that. They might begin by sharing stories of their past and their respective villages. This would lead to a growing understanding of each other.