The traditionalist elders might oppose Naruto. They are used to the old ways of running Konoha and may see Naruto's takeover as a threat to their power and influence.
There could be shinobi who oppose Naruto simply because they don't trust his leadership abilities. They might think that he's too young or inexperienced, despite all his achievements. They may also be influenced by rumors or misinformation spread by those who don't want Naruto in power. These shinobi could form a resistance against Naruto within Konoha.
Some of the powerful ninja clans could oppose Naruto. For example, the Hyuga clan might be worried about how Naruto's rule will affect their position in the village. They may fear that he'll try to change their traditional practices or redistribute their power. Also, some ninja who are loyal to the previous regime may oppose him because they believe that Naruto is overstepping his boundaries.
Well, in such a fanfiction, Naruto might take over Konoha to reform it. Maybe he's tired of the old ways and wants to make it more inclusive and fair for all ninjas, regardless of their background.
Definitely Sasuke. Their bond is such that Sasuke would not stand by and let Naruto destroy Konoha. He has his own reasons to protect the village now. Shikamaru is also a likely candidate. He's intelligent and would quickly figure out that Naruto's actions are wrong. He would use his strategic mind to try and stop Naruto. And Hinata, who loves Naruto deeply, would oppose him in the hopes of bringing him back to his senses.
The elders of Konoha could be the main antagonists. They are often the ones making the big decisions in the village. If Naruto is seeking revenge, it could be because of their actions, like how they treated him when he was a child or how they might have hidden important information from him.
The Hutts would likely oppose Anakin. They have long held power on Tatooine through illegal and immoral means, and Anakin's takeover would threaten their control over the planet's criminal underworld and trade routes.
One possible consequence could be that Naruto grows up away from the influence of Konoha's shinobi culture. He might develop a different set of values and skills. For example, without the guidance of Iruka and Kakashi, his understanding of ninjutsu and teamwork could be very different. Also, his relationships with characters like Sasuke and Sakura would be greatly affected. Maybe he wouldn't have the same rivalry with Sasuke, and his bond with Sakura might not even form.
A 'naruto takes revenge on konoha fanfic' might involve Naruto feeling betrayed by Konoha. Maybe he was wrongly accused of a crime he didn't commit. As a result, he teams up with some of his old enemies who also have grudges against Konoha. Together, they plan a large - scale attack on Konoha. Naruto, with his newfound power and allies, aims to topple the current regime in Konoha and establish a new order where justice is truly served.
Maybe an old hermit who lives in the mountains outside Konoha adopts Naruto. The hermit could be a master of some long - forgotten ninjutsu. Under his tutelage, Naruto would learn these ancient techniques and use them to protect the land around the hermit's dwelling. He might also gain a deeper understanding of nature and chakra from the hermit.
One possible reason could be fear. Naruto has the Nine - Tails within him, and some in Konoha might be too afraid of its power getting out of control. They may not fully trust Naruto to keep it in check.
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 story could develop with Naruto becoming a villain of sorts. He might start attacking other villages or even his own, leading to a big conflict. His friends would then be on a mission to save him.