Maybe some of the Akatsuki members could be his secret allies. For example, Itachi might have had a secret plan and saw Naruto's potential, so he was secretly helping Naruto become stronger all along. Also, there could be some minor characters from other villages who have recognized Naruto's hidden power and decided to ally with him.
It could be Lydia. They have a long - standing relationship in the show, and a secret marriage between them would be quite a shock. Maybe they eloped in a moment of passion and are now trying to figure out how to break the news to their friends.
Maybe some of the younger ninjas from other villages that he has inspired. For example, a young ninja from the Sand Village who saw Naruto's heroics during the Fourth Great Ninja War and now wants to join him in his quests. They could bring new skills and perspectives from their own village's ninja techniques.
An alien race that is highly intelligent but physically weak. They see Naruto as a powerful protector. In return for Naruto's protection, they offer him their advanced technology which could be crucial in his journey back to his world. For example, they might give him a device that can create wormholes to different parts of the universe.
His friends like Sasuke and Sakura could be his allies. Sasuke might be initially skeptical but then see the potential of Naruto's arcane power in fighting common enemies. As for enemies, Orochimaru could be interested in Naruto's power for his own experiments. He might try to capture Naruto to study and steal his arcane abilities.
In some fanfictions, his secret spouse could be an original character created by the author. This character might be a fellow wizard or witch who has a special connection with Snape, perhaps they met during his early years at Hogwarts or in some other part of the wizarding world. They could share a common interest in potions or some other magical art, which brought them closer.
His friends like Sasuke could be his allies. Sasuke, despite his own complex journey, has a deep connection with Naruto. He would understand Naruto's need to fight against the council if they were being unjust. Also, Sakura, with her medical skills and growing strength as a ninja, would be a great asset. She could heal the team during any confrontations and also use her combat skills when necessary.
The other members of Team 7 like Sakura and Kakashi could also be his allies. Sakura could use her medical ninjutsu to heal any injuries Naruto and the team get in space battles. Kakashi could offer his wisdom and combat experience, guiding Naruto in this new and unfamiliar space - filled adventure.
Sasuke could potentially be an ally. Even though they have their differences, in the Akatsuki setting, they might realize they need to work together. Another could be Itachi. Itachi has his own motives and might see Naruto as a key to achieving certain goals within the Akatsuki. Also, Konan could be an ally. She seems to be more open - minded compared to some of the other members and might be swayed by Naruto's positive attitude.
Sasuke could be one of his allies. He might be a rival knight at first but then they realize they have to work together. Sakura could be a healer knight, always there to patch up Naruto and the others after battles. Kakashi could be a wise old knight who gives Naruto advice on knightly matters.
Naruto's allies could include not only his friends from Konoha but also some unexpected characters. Maybe Gaara, as the Kazekage, would form an alliance with Naruto's empire. Their shared experiences of being outcasts in the past could strengthen their bond. Hinata would also be by his side, offering her gentle support and her Byakugan abilities to help in matters of security and intelligence - gathering within the empire.