Who could be the main antagonist in 'naruto saves his younger self fanfic'?

In this fanfic, Naruto might use his time - traveling jutsu accidentally. He could then see his younger self in a dangerous situation, like being attacked by a powerful enemy. So, he jumps in to save him, using all his advanced skills and knowledge. Maybe he also gives some important advice to his younger self to avoid future mistakes.

It could be a new, self - made villain. Maybe a rogue ninja who was once rejected by the Hidden Leaf Village. He blames Naruto for his misfortunes and decides to target his sister as revenge. This villain would have his own set of unique and dangerous jutsu, which Naruto would have to figure out how to counter in order to save his sister.

It could be a rival archer who has a vendetta against the main archer and decides to target his family to get back at him.

It could be a rogue ninja from the Hidden Leaf's past who has come back for revenge. Maybe someone who was wronged by the village long ago and has now amassed great power to destroy it. Another possibility is a new enemy from outside the village, like a powerful warlord from a far - off land who wants to conquer the Hidden Leaf for its resources.

It could be a rogue ninja from Tobirama's time who has a vendetta against the Senju clan. This ninja might have been waiting for the perfect moment to strike at Tobirama when he is alone or vulnerable. Naruto then has to face this powerful and vengeful enemy to save Tobirama.

It could be a rogue ninja who is using the poochyena for some sort of evil experiment. Naruto has to stop this ninja from harming the poochyena.

Perhaps a new and original antagonist could be created for this fanfiction. This antagonist could be a rogue ninja who has mastered a forbidden jutsu that allows him to manipulate time as well. He could be the one who sets up the events that lead to Minato's endangerment, and Naruto has to figure out his motives and stop him while also saving Minato.

Perhaps it's a group of mercenary ninjas. They've been hired by someone who has a grudge against Zabuza. They see Zabuza as an easy target when he's alone or vulnerable, but Naruto shows up to spoil their plan.

Perhaps the main antagonist could be a new character. This new character could be an ancient evil that has been awakened by the presence of the Saiyans on Earth. They see Bardock and Raditz as a threat to their plans of taking over the universe and thus try to eliminate them.

Well, Naruto might try to give his younger self some advice. Maybe he'd tell him to train harder or to be more understanding of Sasuke earlier. It could be a really interesting scenario where the older Naruto tries to prevent some of the bad things that happened in his past from occurring again.