Who could be the main antagonist in a 'naruto juubi crossover fanfic'?

It could be a powerful ninja from Naruto's world who has been corrupted by the Juubi's power and somehow ended up in the Inuyasha world. He wants to use the power of the demons in the Inuyasha world to make himself even stronger and take over both worlds.

Perhaps a rogue Sekirei who has been corrupted by the power of the Juubi's energy that has seeped into the Sekirei world. This Sekirei could start causing chaos, believing that they are now more powerful than the others and should rule over them. Naruto would then have to stop this Sekirei from causing more destruction and bring balance back to the Sekirei world.

It could be a power - hungry noble from the imperial court who sees Naruto as a threat to his own ambitions of ruling. This noble might have his own group of skilled fighters and use underhanded tactics to try and undermine Naruto's rule as emperor.

It could be an evil version of the Sage of Six Paths. He might want to take the Juubi's power from Naruto for his own dark purposes.

It could be Orochimaru from the Naruto universe. He might be interested in the cat's special abilities, perhaps thinking he can use them to gain more power or immortality. He would be a formidable antagonist as he has his snake - like powers and is very cunning.

In a crossover with Snow White, the Evil Queen could be the main antagonist. She might be jealous of Tinkerbell's magic and try to capture her to use her pixie dust for her own dark purposes.

From the Selda side, Link could be a main character. He is used to fighting against great evils in his own world. If the Juubi were to invade, Link would be a natural ally for Naruto and the others. His skills with the sword and his ability to navigate through different terrains would be very valuable in a battle against the Juubi - influenced threats in the Selda world.

One possible plot could be that the Juubi somehow gets transported to the Naruto world during a strange rift in space - time. Naruto and his friends have to figure out how to deal with this powerful and chaotic entity. They might initially try to fight it, but then realize they need to find a way to seal it again, like they did with the other tailed beasts. This could lead to new alliances and power - ups for the characters as they struggle to protect their world.

Perhaps an ancient evil that has been sealed away in the empire for centuries but is released due to the chaos of the crossover. This entity could be more powerful than any foe the Naruto characters have faced before, forcing them to find new ways to fight.

A group of rogue shinobi and some of Daria's school bullies could team up. The shinobi would give the bullies some ninja powers, and together they would cause trouble in both worlds. This group would be difficult to deal with as they combine the physical strength of the shinobi with the local knowledge of the bullies.