The Saiyan's power is mainly based on their physical strength, ability to transform, and use of ki. Naruto has his chakra, with the Nine - Tails' chakra being a major part. Kaguya has her own powerful chakra and unique abilities like the All - Killing Ash Bones. In a fanfic, the Saiyan's physical might could be a match for Kaguya's brute force attacks. Naruto's chakra - based jutsu could be used to complement the Saiyan's attacks, for example, using shadow clones to create diversions while the Saiyan attacks directly. Kaguya's reality - warping abilities would pose a huge challenge to both the Saiyan and Naruto, forcing them to come up with new strategies together.
Well, one possibility could be that Naruto, with his Saiyan powers (assuming some sort of crossover mechanic), has to deal with Kaguya in a new way. Maybe he forms a harem that includes characters related to Kaguya's story. The plot could involve battles against new threats while also exploring the relationships within the harem.
Naruto is a must. Kaguya, as a key part of the Naruto lore, would be in it. In terms of the harem, Ino could be one of the characters. She has always had an interest in Naruto to some extent. Tenten could also be part of it, perhaps drawn to Naruto's new Saiyan - like strength. And from the Saiyan side, Raditz could be introduced, creating some conflict as he initially tries to take advantage of Naruto's Saiyan powers but later might become an ally. There could also be some original characters created just for this fanfic.
One possible plot could be a crossover where a Saiyan somehow ends up in the Naruto universe during the time of Kaguya. Maybe the Saiyan's power is sensed by Kaguya and she sees it as a threat or an opportunity. The Saiyan, with their battle - hardened nature, could get involved in the Naruto characters' fight against Kaguya, adding a new dimension of power and strategy to the battle.
Kakashi can be a popular character too. His wisdom and combat skills can be useful in fanfic scenarios involving Kaguya. He could be a mentor figure to Naruto, guiding him in dealing with Kaguya - related threats or helping to decipher ancient ninja knowledge related to Kaguya.
One common theme is redemption. Since Kaguya was initially a villain, many fanfics explore her journey towards redemption with Naruto's help. Another theme is power. How their combined powers can be used for different purposes, like protecting the ninja world. For example, in some fanfics, they use their powers to fight off a new threat that is stronger than any they've faced before.
One good Naruto x Kaguya fanfic is 'The Last Dance'. It explores an alternate universe where Naruto has to team up with Kaguya against a new, powerful enemy. The story does a great job of building their relationship from mutual distrust to a deep understanding.
One great 'Naruto Uchiha Kaguya Fanfic' is 'The Legacy of Kaguya'. It delves deep into the backstory of Kaguya and how it ties to the Uchiha clan in Naruto's world. The character development is really well - done and it keeps you hooked from start to finish.
A unique feature is the expansion of the Naruto universe's lore. Fanfics about Kaguya can introduce new powers, ancient prophecies, or hidden civilizations related to her. They can also bring in other characters in new ways, making them interact with Kaguya and Naruto in unexpected relationships. For instance, a side character might become the key to understanding Kaguya's true intentions. Moreover, the fanfics can explore different endings or consequences of Kaguya's actions in the Naruto storyline, which gives readers a fresh perspective on the whole Naruto - Kaguya saga.
One great 'Naruto Kaguya Otsutsuki Fanfic' is 'The Legacy of Kaguya'. It explores her backstory in a very detailed way. It shows how she came to be the powerful being she was in the Naruto series. The author does a great job of creating new scenarios that fit well with the existing Naruto lore.