A plot where they are both chosen to be part of a special team for a multi - universe tournament. They have to learn to work together despite their differences. Naruto with his raw power and Azula with her strategic mind could create some really interesting battle scenarios against opponents from other universes. They might start off not getting along but gradually develop respect for each other as they face tougher challenges.
Another interesting plot could be that a powerful enemy is using some sort of dark magic or jutsu to merge the two universes. Naruto and Azula are among the first to notice the strange happenings. They have to put aside their initial distrust and combine their powers to stop the chaos. Along the way, they could also meet other characters from both universes and form a larger alliance to save both their worlds.
One interesting Naruto x Azula fanfiction could be where Naruto, with his unwavering belief in people, meets Azula, who has a complex and troubled past. He tries to show her a different path, and they embark on adventures together, learning from each other's cultures and powers. For example, Naruto could teach Azula about the power of friendship, while Azula could introduce Naruto to the strategic warfare of her world.
One idea could be that Azula, with her firebending skills and strategic mind, is somehow transported to the Harry Potter universe. She could be sorted into Slytherin and form an unlikely alliance with Draco Malfoy. They might plot together to gain power within Hogwarts, using Azula's manipulation tactics.
In a fanfiction, it could be that there is a prophecy that involves both Percy and Azula. The prophecy states that only by combining the skills and powers from their respective worlds can they save a third, unknown world that is on the brink of destruction. This forces them to work together and overcome their differences as they journey to discover what they need to do to fulfill the prophecy.
Well, she could go back in time and end up in a situation where she has to team up with her former enemies. This would be a great chance to explore her character development as she has to work with people she once despised. Also, she might go back and try to take over the Fire Nation at an earlier time, using her future knowledge of combat and strategy.
One idea could be that Naruto and Kashuina meet during a mission outside of Konoha. They start off as rivals, constantly trying to outdo each other in combat skills. But as they face various challenges together, they gradually develop a mutual respect and then deeper feelings. Another plot could be set in a post - war scenario where Naruto, now a hero, meets Kashuina who has a unique ability to heal the psychological scars of the war - torn ninjas. Their interaction then leads to a romantic relationship. And a third idea is that they are both students under a new sensei who pairs them up for special training. During this training, they discover things about each other that they never knew before and fall in love.
One idea could be Naruto being sent to the world of Death Note. He could use his ninja skills to try and outwit Light Yagami. Maybe he would initially be confused by the Death Note's power but then use his determination to stop Light from his killing spree. Another plot could involve Naruto meeting the Shinigami. He might learn about the balance between life and death in this new context and try to find a way to bring some of his ninja world's values to this strange new world.
Perhaps Naruto and Lala meet during a mission where Naruto is sent to a different dimension. Lala, being from an alien world, is intrigued by Naruto's determination and they form an alliance to face a common enemy in that dimension. Their different powers and abilities complement each other, and as they work together, they start to develop feelings for each other.
A more complex plot could be that there is a prophecy in both worlds about a union between someone from the Naruto universe and someone from Ruby's universe. Naruto and Ruby are the ones fated to fulfill this prophecy. They initially don't get along but as they face various challenges together, they start to understand each other and fall in love, while also saving both their worlds in the process.
In a naruto x avatar fanfiction, there could be a scenario where the Akatsuki from Naruto's world teams up with some of the villains from the Avatar world. This would force Naruto and the Avatar (whichever one it may be) to put aside their differences and form an alliance with other characters from both worlds to stop this powerful and evil coalition.
One idea could be that a zombie virus spreads in the Naruto world. Naruto and his friends have to not only fight the zombies but also figure out how the virus started. Maybe Orochimaru was experimenting with dark jutsu and it went wrong.