Well, one possible plot could be that Louise from Zero no Tsukaima somehow gets transported to the Naruto world. Maybe she mistakes Naruto for a familiar at first. And Naruto, being his curious self, would be intrigued by Louise's magic. They could team up to fight against common enemies, like some rogue ninjas who are after Louise's magic or some dark forces in the Naruto world that see Louise as a threat.
Another idea is that a villain from the Zero no Tsukaima world follows Louise to the Naruto world. This villain teams up with some of the more evil - minded ninjas in Naruto. Together, they plan to take over both worlds. Louise and Naruto then have to gather their friends and allies from both worlds, including Saito from Zero no Tsukaima and Sasuke (if he's on the good side at that point). They would then engage in a huge battle to save both their worlds from this combined evil.
One possibility could be a world where the post - apocalyptic setting of Fallout meets the magic - filled world of Zero no Tsukaima. Maybe the main character from Fallout somehow gets transported to the Zero no Tsukaima world. They could bring with them their survival skills and unique technology, which would be very strange and new in the magical world. This could lead to all kinds of adventures, like trying to adapt to the different social and magical systems while also trying to find a way back home.
One idea could be to cross it with a modern - day world. Imagine Louise and Saito suddenly finding themselves in a bustling city. They would have to deal with technology they don't understand, like smartphones and cars. Another plot could involve a crossover with a magical school from another series. The characters could exchange magical knowledge and spells.
Louise would probably be very haughty and proud at first when interacting with the Naruto characters. She might look down on them for not having magic. However, Naruto's positive and friendly attitude would slowly break down her walls. Saito, on the other hand, would be more adaptable. He might get along well with some of the more laid - back ninjas like Shikamaru. They could bond over their loyalty to their respective partners (Louise for Saito and Temari for Shikamaru perhaps).
Well, one unique feature is the combination of different fictional elements. For example, it might bring in characters or concepts from other fantasy or sci - fi worlds. This creates a whole new and exciting story universe.
It could be that the baby has some unique magical abilities that start to manifest at a very young age. This causes a stir in the magical community. Louise and Saito have to deal with the attention, both good and bad. Some might see the baby as a threat while others see it as a hope for a better future. They would need to navigate through the politics and power plays in the magical world while raising their baby.
There's 'Zero's New Adventure in a Crossover'. In this fanfiction, Louise and her familiar Saito find themselves in a crossover situation with a post - apocalyptic world. They have to use their magic and sword - fighting skills to survive and find a way back home. It's full of action and some really interesting character interactions.
Another plot idea could be focusing on the backstories of the secondary characters in 'zero no tsukaima' within the fanfic. For example, we could learn more about Siesta's life before she came to the academy. It could add more depth to the overall story world and create new sub - plots.
You could include characters like Harry Potter. His knowledge of magic from the Hogwarts world would contrast and interact interestingly with Louise's magic from 'zero no tsukaima'. Another good character could be Naruto. His determination and unique ninja skills would add a different dynamic to the story when combined with Saito's swordsmanship.
The characters from Fallout are often tough and resourceful due to the harsh post - apocalyptic environment. They might initially be very cautious and even distrustful when interacting with the more flamboyant and magical characters from Zero no Tsukaima. For example, a Vault Dweller from Fallout might be suspicious of a mage's motives in Zero no Tsukaima. However, as they face common enemies or challenges, they could start to work together and learn from each other.
One interesting concept could be alternative timelines. Writers might explore what would happen if certain events in the original 'zero no tsukaima' series occurred differently. For example, if Louise had chosen a different familiar. Another concept could be character development beyond what was shown in the anime or manga. Maybe Saito becoming even more powerful in magic in ways not originally depicted. And also, exploring different relationships between the characters, like a deeper friendship between Louise and her classmates that was only hinted at in the original story.