Perhaps in this fanfiction, Naruto's clones could be used in a creative way in the Familar of Zero setting. For example, his clones could be used to perform different magical tasks simultaneously, which is not possible in the normal Naruto world. This could lead to some really interesting and comical situations.
One idea could be a crossover of Naruto's world and the Familar of Zero world where Naruto has to learn the magic system in the new world. Maybe he teams up with Saito from Familar of Zero to fight a common enemy.
Another plot idea could be that the characters from Familar of Zero are brought into the Naruto world. They might be shocked by the shinobi abilities and the large - scale battles. And Naruto could teach them some of his ninja skills while they in turn show him their magical knowledge, creating a great exchange of cultures and abilities within the fanfiction.
Perhaps in the fanfiction, the Zero Tails is a manifestation of the negative emotions of the ninja world as a whole. A group of young ninjas discover this and they try to find a way to purify the Zero Tails. They seek the help of old sages and learn ancient jutsu to attempt this purification, which could lead to a battle against those who want to keep the Zero Tails as a weapon of mass destruction.
One idea could be exploring new ninja techniques not seen in the original Naruto series. For example, a unique combination of elemental jutsus created by a character in 'naruto ruler zero fanfiction'.
Sakura from Naruto might interact with Louise from Familar of Zero. Both are strong - willed female characters. They could start off as rivals, competing in areas like magic vs medical ninjutsu, but then gradually become friends and learn from each other's strengths.
One idea could be a crossover where Naruto characters end up in the world of Familiar of Zero. For example, Naruto could meet Louise and they team up to face a common enemy. Maybe an evil mage from the Familiar of Zero world is trying to steal chakra, and Naruto uses his skills to protect everyone. Another plot could be about a character from Naruto becoming a familiar in the Familiar of Zero world, which would create a lot of comical and interesting situations as they try to adapt to the new rules and customs.
One idea could be to create a crossover where Naruto characters are transported to the world of Familiar of Zero. For example, Naruto could be mistaken for a powerful familiar. Another idea is to have a character from Familiar of Zero learn ninjutsu from Naruto. Maybe a familiar in the Familiar of Zero world could have the Nine - Tails' chakra sealed within it.
One plot idea could be that Zero Two and Naruto are from different universes but are brought together by some sort of magical or scientific accident. They then have to team up to fight a common enemy that is threatening both of their worlds. Another idea could be that Zero Two somehow ends up in the Naruto world and has to adapt to its ninja culture while also using her unique abilities to help Naruto and his friends on a mission. Maybe she could even learn some ninja techniques herself.
One idea could be Naruto being summoned as a Servant in the Fate Zero world. His unique ninja abilities would make for an interesting dynamic against the traditional Servants. He could use his shadow clones to outnumber opponents or his Rasengan in combat.
One idea could be a crossover where Naruto characters gain the abilities of Mega Man Zero. For example, Naruto could use Zero's saber in combat, adding a new dimension to his fighting style. Another idea is a story where the world of Naruto is invaded by enemies from the Mega Man Zero universe, and the ninja have to adapt quickly to survive. Maybe even a story where Mega Man Zero is somehow transported to the Naruto world and has to learn about chakra and ninja techniques to find his way back home.
One idea could be that the patient zero OC has a unique ability to heal others despite being the origin of a disease. This creates a moral dilemma within the story as people are both afraid and in need of their power.
One interesting plot idea could be exploring the backstories of the characters in more depth. For example, delving into how they got their powers in this Sub Zero setting. Another could be a new villain emerging and the team having to adapt their fighting styles.