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.
One common plot twist could be that Naruto sees a future where his friends turn against him, but then discovers it was an illusion created by a new enemy. Another might be that he sees a future where Konoha is destroyed and has to find a way to change that fate. Maybe he sees a future where he becomes a villain himself and has to struggle to prevent that from happening.
One common plot twist is that Haku's true identity is related to Naruto's family in a more complex way than just being siblings. Maybe they are part of a long - lost clan. Another is that their combined powers lead to a new and unexpected ability that changes the course of the Naruto world. For example, they might be able to combine their ice and wind - based techniques in a unique way.
One common plot twist could be that the masked demon is actually a misunderstood entity. Maybe it was once a good-natured being that was corrupted by some dark force. For example, it could have been a shinobi who was experimented on and the transformation into the masked demon was involuntary. Another plot twist might be that the masked demon has a connection to Naruto's family that he was unaware of. It could turn out that the demon was bound by an ancient curse placed by one of Naruto's ancestors. A third plot twist could be that the masked demon is not truly evil but is being controlled by a greater, more insidious evil. Naruto then has to find a way to break the control rather than simply defeat the demon.
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.
The devil could be a new, mysterious character created specifically for the fanfiction. It might be an ancient evil entity that has been lurking in the shadows of the Naruto world for ages.
One common plot twist could be Naruto being influenced by a dark power. For example, he might encounter an ancient evil entity that corrupts his mind, leading him to turn against his friends and the village. Another could be a betrayal within the village that makes Naruto lose faith in his values and start to embrace a more self - serving and ruthless attitude.
One common plot twist could be that Naruto discovers some of his friends have been secretly bitten and are turning into zombies. For example, Sasuke might get bitten but try to hide it from Naruto at first. Another could be that the zombie virus is actually created by an old enemy of the Hidden Leaf Village who has found a new way to attack. Maybe Orochimaru had something to do with it and his experiments went wrong, leading to the apocalypse.
One common plot twist could be Naruto discovers a hidden healing jutsu that has a dark side. For example, it might drain his life force while healing others at an extraordinary rate. Another could be that he's forced to choose between using his medic nin skills to save a friend or use them to stop a powerful enemy, as using the skills in one way would make it impossible to do the other. And sometimes, he might find out that his medic nin abilities are linked to an ancient prophecy that no one expected.
One common plot twist could be that Naruto is chased out due to a false accusation. For example, he might be wrongly blamed for a major crime in Konoha. Another could be that a powerful and secretive group within Konoha sees Naruto as a threat to their hidden plans and arranges for his expulsion. Also, it might be that Naruto discovers some dark secrets about Konoha's leadership and they try to silence him by chasing him out.