Who could be the main antagonists in Harry Hook sister fanfiction?

Voldemort's remaining followers could be antagonists. They might target Harry's little sister thinking they can use her to get to Harry. They could try to kidnap her or use dark magic on her.

The Ministry of Magic could be the antagonists. Since Harry is in a gang, they might see him as a threat to the order of the wizarding world. They could send Aurors after him and his gang mates, trying to arrest them and break up the gang.

The Foot Clan could be a main antagonist. They might see the baby sister as a way to get to the turtles, either by kidnapping her or using her to blackmail them. Another could be Shredder himself if he returns. He would surely not pass up the opportunity to use the baby sister against the turtles. And Baxter Stockman could also be an antagonist. He might be interested in using the baby sister for some of his mad - scientist experiments.

The Akatsuki could be the main antagonists. Since Naruto is an important target for them, and if Kurenai is now his sister, they might see her as an obstacle in their way. They could try to use their various powers and strategies to either capture Naruto or cause harm to both him and Kurenai.

Voldemort's remaining followers could be the antagonists. They might see Harry's little sister as a way to get revenge on Harry or as a potential tool for their dark purposes.

Perhaps the very magic that made Harry a god has a sort of negative side - effect. This could manifest as a shadowy entity within Harry that tries to take over his mind and use his powers for evil. So, in a way, this internal struggle could be the main antagonist in the story.

Some jealous students at Hogwarts could also act as antagonists. They might be envious of Harry's newfound allure and use underhanded tactics to try and make his life difficult.

Voldemort or his followers could still be antagonists. They might not like the idea of Harry being under Euryale's protection as it could make him more powerful. Another possibility could be some creatures from Euryale's world who are against her taking in an outsider like Harry.

It could be some jealous rivals of Arcuid. They might see Harry as an outsider and a threat, especially if they think Arcuid is giving Harry special treatment or powers. Maybe there are those who want to use Harry against Arcuid for their own gain.

The Ministry of Magic could be antagonists. If they start to oppress those with different views, including Harry, it could drive him towards darkness. Their corrupt and unjust actions might make Harry think that the only way to fight back is by using dark magic.