In some Naruto heaven and earth fanfictions, the concept of reincarnation is explored in a new way. For example, a character is reincarnated with the memories of both a celestial being and an earth - bound spirit. This gives them a different perspective on the ninja world and they try to reshape it according to their combined knowledge of the two realms.
One interesting plot could be about a new character in the Naruto universe who has the power to control both heaven and earth elements. They could use this power to try and bring peace between warring clans.
Maybe a fanfiction where Naruto discovers a hidden realm that is a combination of heaven and earth, and he has to learn new jutsus there to defeat an upcoming threat. This realm could have unique creatures and powers that Naruto has to adapt to. It would be a great adventure story, full of self - discovery for Naruto.
Another idea is Sasuke and Sakura in the '7 minutes in heaven'. Sasuke, who is often aloof, could be forced to confront his feelings for Sakura in that small, confined space. Maybe they start arguing at first, but then as the minutes tick by, they recall all the times they've been through together and it softens their relationship a bit. For example, Sakura could mention how she's always worried about him during his travels, and Sasuke might show a glimmer of his true feelings for her.
Another idea is that the Earth Grudge Fear gives Naruto the ability to communicate with the spirits of the earth. These spirits can either help him or hinder him depending on his actions. He could use this connection to discover hidden shinobi techniques or lost knowledge. But there are also dark spirits that try to corrupt him, and Naruto has to resist their influence. His friends don't understand this new side of him at first, and he has to prove that he can control it.
One idea could be Naruto arriving on Earth during a major global crisis, like a widespread natural disaster. He could use his ninja skills to rescue people. For example, his shadow clone jutsu would be very useful in searching for survivors in multiple locations at once.
One idea could be Naruto being transported into the Heaven's Feel world and having to deal with the Grail War using his ninja skills. Another could be a crossover where the characters from Naruto interact with the Heaven's Feel characters in unexpected ways, like Naruto befriending Shirou and teaching him some ninja techniques.
The plot could involve Naruto and Sakura being sent to a realm that is a mix of Heaven and Earth by some ancient force. There, they encounter spirits and beings that teach them new forms of ninjutsu. Naruto could learn a Heaven - based jutsu, like summoning celestial animals, and Sakura could learn an Earth - based one, like manipulating the land's energy. As they progress, they have to fight against an evil that wants to disrupt the harmony of this unique world.
One idea could be a crossover of characters from different Arrowverse shows on Earth X. For example, having Barry Allen from 'The Flash' team up with Kara Danvers from 'Supergirl' to fight against the evil regime on Earth X. They could use their super - speed and super - strength respectively to take on the powerful foes there.
Maybe there's a fanfiction where a Sith Lord tries to take over Earth. The Earth's military would be no match for the Sith's powers at first. But then, through some clever thinking and the discovery of a hidden Earth - based energy source similar to the Force, they start to fight back.
For 'a child of earth and sky fanfiction', a plot idea could be centered around the character's discovery of an ancient civilization that was closely tied to the earth and sky. They learn the secrets and wisdom of this civilization which gives them new abilities. They then use these abilities to face a natural disaster that threatens to destroy the balance between the earth and sky. Along the way, they form bonds with other characters who also have a connection to the earth and sky, and together they fight to preserve the world as they know it.
One idea could be a crossover where the Naruto characters end up in the world of Heaven Lost Property. Naruto's skills in combat and his determination could create some really cool scenarios when faced with the angels and devils in that world.
A plot idea could be that Naruto discovers a new, ancient form of chakra that has been lost for centuries. He then has to train to master this chakra while also dealing with the political implications within the Hidden Leaf Village. Some elders might be against him exploring this new power for fear of the unknown, but Naruto, being Naruto, is determined to master it for the good of the village.