Who could be the main antagonist in 'harry is half demon fanfiction'?

It could be a powerful ninja from another village who is jealous of Naruto's half - demon half - god powers. He might see Naruto as a threat to his own village's dominance and try to eliminate him.

Maybe a rogue ninja who has been experimenting with dark magic. He discovers Naruto's unique nature and wants to steal his power. He believes that by combining Naruto's angel and demon fox powers, he can become invincible. So, he sets out to hunt Naruto down and tries every trick in the book to get his hands on that power.

Orochimaru would be a great main antagonist. He's always been interested in power and the secrets of the body. Naruto's half - demon fox nature would be a prime target for his experiments. He could try to extract the power of the demon fox from Naruto, or use Naruto as a way to create his own brand of super - soldiers with demon - like powers.

It could be a powerful ninja who has made a deal with an otherworldly force to gain powers to match Naruto's. This antagonist might be jealous of Naruto's unique heritage and wants to prove that pure ninja power is superior. So, he uses dark magic or forbidden jutsu to become a formidable foe.

It could be a rogue god who sees the half - robot as a threat to the natural order. They might try to destroy it because they don't like the idea of a half - human, half - machine being in the world of demigods. Another possibility is a powerful Titan who was awakened and wants to use the half - robot's technology for their own evil purposes. Maybe the half - robot has some sort of power source that the Titan desires.

It could be a rogue ninja who has made a pact with the demons in the demon world. This ninja has turned against the ninja world and wants to use the power of the demon world to rule over all. He would constantly oppose Naruto's attempts to restore peace.

It could be an ancient demon lord who wants to enslave both the demon prince and Naruto. This demon lord might see the unique bond between them as a threat to his plans of domination.

Obviously, the demon overlord could be the main antagonist. He might have his own motives like ruling the ninja world or obtaining some powerful jutsu that Naruto and his friends are trying to protect.

A new dark wizard who has emerged from the shadows, someone who idolized Voldemort and is trying to pick up where he left off. This antagonist could be using new and more insidious magic that Harry has to figure out how to combat as an Auror.

A power - hungry noble could be the main antagonist. This person might be jealous of the Queen's position and wants to overthrow her, and sees Harry as an obstacle in his way.