Who could be the main antagonists in a 'harry adopted by euryale fanfiction'?

In a 'harry adopted by euryale fanfiction', it could start with Harry being lost or on the run. Euryale, seeing his potential or feeling a connection, decides to adopt him. She could introduce him to a whole new world of magic that is different from what he has known in Hogwarts. For example, a magic more related to the ancient Greek mythology which she is a part of. And Harry would have to adapt to this new life and learn from Euryale while also dealing with any threats that might come from his past in the wizarding world.

The Joker could be a main antagonist. He would be fascinated by Harry's magic and would try to use it for his own evil purposes or just to cause chaos. He might try to drive a wedge between Harry and Batman by using mind games.

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.

One possible main antagonist could be Voldemort still. Even though Harry is now under Sparda's protection, Voldemort would see Harry as a threat and would try to get rid of him. Another could be some of the demons from Sparda's world who see Harry as an intruder or a threat to their plans in the new world order that Sparda is trying to create with Harry by his side.

Definitely Voldemort. He's the main baddie in the Harry Potter series. But in this fanfiction, there could be other villains too. Maybe some jealous Disney characters who don't like Harry getting all of Mickey's attention. Or some dark forces from the edges of both the wizarding and Disney worlds that team up with Voldemort to stop Harry and Mickey's new family dynamic.

It could be another magical creature or group that is jealous of the power that the vixen holds and by extension, Harry as her adopted son. Maybe there is a group of dark wizards who want to harness the vixen's magic through Harry, and they become the antagonists as they try to capture him.

The shinobi council could be antagonists. They would be very suspicious of Naruto being adopted by Jenova, fearing that he will bring destruction to the village. They might try to isolate or even eliminate Naruto.

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 Titans could still be antagonists. Even though Percy is now associated with Artemis, the Titans might see him as a threat or a tool to use against the gods. Kronos, for example, could try to turn Percy to his side by offering him power or by threatening those he cares about in Artemis's group.

The Olympian gods could be the main antagonists. Since Percy is the adopted son of Kronos, they might see him as a potential threat and try to stop him before he can fulfill any of Kronos' possible plans. They may send their demigod heroes after him.