Who could be the main antagonist in 'Hwrry Potter discovers chakra fanfiction'?

One possible plot could be that Harry Potter, while on one of his adventures outside of the wizarding world, stumbles upon a hidden group that practices chakra. They initially see him as an outsider but as he shows his own magical prowess, they start to teach him about chakra. He then tries to combine the two forms of power, facing challenges along the way like resistance from some in the wizarding world who fear this new form of magic he's bringing in.

It could still be Voldemort. Even with the introduction of the Tensaiga, Voldemort would remain a major threat. He might become even more interested in the Tensaiga once he learns about it, seeing it as a powerful tool to achieve his dark goals.

Well, if Harry Potter discovers chakra, he could potentially gain new magical abilities. He might be able to combine his existing wizardry with chakra - based powers. For example, he could use chakra to enhance his spell - casting speed or strength. Maybe he could even develop new spells that are a fusion of the two magic systems.

It could be a jealous ninja from another village who sees Naruto's infinite chakra as a threat to their own village's power. This ninja might try to steal Naruto's chakra source or find a way to nullify it.

It could be a rogue ninja who is also after the power of the chakra chains. This ninja might see Naruto as a threat and try to eliminate him to get the chains for himself.

Perhaps a long - lost relative of the Potter family who feels they were unjustly excluded from inheriting the manor. This relative could be jealous of Harry's status and the wealth associated with the manor. They might use dark magic to try and claim what they think is rightfully theirs, leading to a battle of magic and loyalty within the Potter family and among Harry's friends.

Maybe there could be a new antagonist, a dark shapeshifter who is jealous of Harry's power. This antagonist could be an old wizard who has been in hiding for centuries, waiting for the right time to emerge and take over the wizarding world. He sees Harry as a threat to his plans and tries to eliminate him.

Another possibility is a corrupted member of the Ministry of Magic. They might be trying to use Harry as a scapegoat to gain more power within the Ministry. They could be working with the Death Eaters or acting on their own, but they would be a significant obstacle for Harry as he tries to stay alive and free while on the run.

Perhaps a new dark wizard or witch who has infiltrated the Ministry of Magic and made sure Harry was sent to Azkaban. This antagonist could be working towards a bigger plan to take over the wizarding world and sees Harry as a major threat even when he's locked up.

It could be Voldemort. He might see Harry's new waterbending ability as a threat and try to find a way to counter it. Maybe he would seek out dark magic related to fire to oppose Harry's water powers.