A plot twist could be that the singing and dancing are actually a form of ancient ninja art that was lost. The devil knows this art and by dancing and singing with Naruto, is passing on this knowledge. However, this art has a dark side that Naruto has to overcome. He has to use his own values and the power of friendship to transform this potentially dangerous art into something positive.
Well, it could be that Naruto discovers this song during a mission in the modern world. Maybe he starts singing it to cheer up his comrades when they're feeling down. The lyrics might resonate with his own struggles against the Nine - Tails inside him, like how the song talks about inner demons.
The plot could involve a mysterious figure who uses a singing jutsu during the Chunin Exam. This jutsu affects the minds of the participants, causing them to act out of character. Naruto, with his strong will, is able to resist it to some extent. He then teams up with some of the other genin to figure out who is behind the jutsu and stop it. Along the way, they all have to sing in order to counter the effects of the jutsu, leading to some comical and heartwarming moments.
Another plot twist could be that Naruto discovers that the deal he made with the devil was a setup by an even greater enemy. So, while he thought he was getting power or knowledge from the devil to help his friends and the village, it was all part of a larger scheme to bring chaos. He then has to find a way to break the deal without losing his soul or something equally important.
One common plot twist could be that the devil game turns out to be a test by an ancient ninja clan. For example, they use it to find worthy successors. Another might be that the game is actually a trap set by an enemy ninja to weaken the main characters. They lure them into the game with false promises of power.
Maybe a plot twist could involve their family history. There could be a hidden enemy that targeted their family long ago, and now they have to face this threat together. As they dig deeper into their past, they find out secrets that change their view of themselves and their powers. It could also be that their brotherhood is a key to unlocking an ancient prophecy.
One possible plot twist could be Naruto having to deal with the expectations of the Greek pantheon. Since Athena is known for her wisdom, Naruto might struggle to live up to that intellectual standard while still maintaining his ninja way. For example, in battles, he might be expected to use more strategic thinking rather than just brute force.
Well, a plot twist might be that Naruto discovers Anko has a hidden power that she's been suppressing. This power could be related to a rare bloodline or a forbidden jutsu. As they start dating, Naruto notices strange occurrences around Anko and eventually uncovers this secret. This could create a rift between them as Naruto might be worried about the implications of such a power, while Anko is afraid of being rejected because of it. Also, there could be a plot twist where the Akatsuki targets Anko because of her relationship with Naruto. They might see her as a way to get to Naruto and try to kidnap or manipulate her.
A plot twist could be that Koharu has a connection to an ancient and powerful jutsu that she passes on to Naruto. However, this jutsu comes with a dark side or a price. Naruto then has to struggle with using this power for good while also dealing with the negative consequences it brings. He might have to make some difficult moral choices that test his character in ways he hasn't been tested before.
A plot twist might be that Naruto discovers that the Akatsuki was actually formed with good intentions in the past, but got corrupted over time. As the leader, he decides to go back to the original purpose. He then has to fight against the current power - hungry members while also trying to convince the other villages that the Akatsuki can be a force for good again. This would create a lot of tension and interesting character dynamics.
One possible plot twist could be that Naruto joins the Akatsuki to spy on them for Konoha. But as he spends more time with the members, he starts to understand their motives, which are not all as evil as he initially thought. For example, some might be seeking revenge for past wrongs done to their villages.