Another possibility is that there is no single main antagonist. It could be a combination of misunderstandings, village politics, and personal issues within Kurenai herself that lead to her betraying Naruto. For instance, the village elders might be pressuring Kurenai to keep Naruto in check, and at the same time, Kurenai has her own doubts about Naruto's power which could be misconstrued as a reason to betray him.
It could be a rogue ninja from a hidden village who has a vendetta against Konoha. This ninja might target Kurenai and Anko specifically because of their skills and knowledge, and Naruto gets in the way while trying to protect them.
Well, it could be that Kurenai is somehow deceived into believing Naruto has done something really bad. Maybe she's tricked by an enemy who fakes evidence against Naruto. So, in her misunderstanding, she turns against him.
Obviously, Kami would be the main antagonist. Since the title says 'naruto betrayed by kami', Kami is the one doing the betraying, which makes him the bad guy in this fanfiction.
It could be one of the harem members who has a hidden dark side. Maybe she's jealous of Naruto's closeness to others in the harem and decides to turn the rest against him, so she becomes the main antagonist.
Another possibility is that there is a false god or a demon that has influenced the true gods to betray Naruto. This false entity could be the real mastermind behind the whole situation. It wants to use Naruto's downfall to gain more power or to bring chaos to the ninja world. So Naruto not only has to deal with the betrayed by the gods part but also has to uncover the true source of this conspiracy which is this false god or demon.
It might be a rogue ninja from the Wave. They could have a vendetta against Konoha and see Naruto as an easy target to frame and cause chaos between the two places.
It could be a new character, someone who is jealous of Naruto's growing power and popularity among the girls. This person might spread false information to turn everyone against Naruto. Maybe a rogue ninja who has infiltrated the village and has a vendetta against Naruto for some unknown reason.
The Jedi Council themselves could be the main antagonists. Since they are the ones betraying Naruto, they would be the ones he has to oppose. Their actions of betrayal would drive the conflict in the story.
It could be a jealous Fairy Tail member. Maybe someone who is envious of Naruto's unique powers and the attention he gets from some of the guild members. This person could start spreading lies about Naruto to turn the others against him.
It could be Xehanort. He's a powerful and devious character in Kingdom Hearts. If he sensed Naruto's power and saw him as a threat, he might engineer a situation where Naruto is made to feel betrayed. Xehanort could manipulate the events and the people around Naruto to make it seem like his new friends in the Kingdom Hearts world are against him, all so that he can either eliminate Naruto or turn him to his side.