Well, an interesting infiltration in a Naruto fanfiction could be into the Hidden Sand Village. Suppose a character from Konoha is sent to discover some secrets about the Sand's new defense mechanisms. They could disguise as a traveling merchant. Also, infiltrating the Leaf Village from an outside perspective can be cool. Like a rogue ninja trying to steal some secret scrolls from the Hokage's office.
One idea could be for a character to infiltrate the Akatsuki. They might pretend to be a new recruit with a special skill. For example, they could say they have a unique jutsu to spy on other villages. Another idea is infiltrating Orochimaru's lair. Maybe a young ninja goes undercover to find out Orochimaru's next big plan. They'd have to be really careful as Orochimaru is very cunning.
Sasuke could potentially be an infiltration master in fanfiction. He already has the Sharingan, which gives him an edge in observing and predicting movements. He could use his skills and his dark past to become someone who can infiltrate any place. Maybe he uses his knowledge of different ninja clans and their weaknesses to his advantage while infiltrating.
A lesser - known but really engaging 'Naruto Infiltration Specialist' fanfiction is 'The Hidden Infiltrator'. It delves into the backstory of the infiltration specialist, showing how they came to develop their skills and their motives for using them in the Naruto universe.
Well, it's captivating because it often takes the original Naruto world and adds new, exciting twists. The idea of an infiltration master brings in a whole new level of stealth and strategy. It can show different sides of the characters we already know and love, like Naruto or Sasuke, as they deal with this new kind of threat or ally. It also might introduce new characters who are experts in infiltration, and their skills and backstories can be really interesting to explore.
One interesting idea could be the combination of Naruto's ninja skills with mecha technology. For example, Naruto might use his chakra to power up the mecha in unique ways. Another idea could be the new enemies that are created specifically for this mecha - Naruto concept, like robotic shinobi that require different combat strategies compared to normal foes. Also, the design of the mecha Naruto itself can be really cool, perhaps with features inspired by the Nine - Tails.
Often, the characters who interact with the infiltration specialist are also quite engaging. Naruto himself can be very interesting in these fanfictions. When he meets the infiltration specialist, his naivete about stealth and infiltration can create humorous and also educational moments as he learns from the specialist.
Another idea is that Aizen somehow ends up in the Naruto universe during the time of the Fourth Great Ninja War. He could try to manipulate both sides for his own gain. But Naruto, with his ability to see the good in people, might try to reason with Aizen and show him a different path. It could be a story of redemption or a great battle if Aizen refuses.
In a 'Naruto Mermaid Fanfiction', the mermaids could be in danger from an evil organization that wants to capture them for their precious scales. Naruto teams up with a mermaid princess to stop this threat and in the process, they learn about each other's worlds.
One idea could be a crossover where Naruto and Pucca end up in the same world due to a strange ninja jutsu gone wrong. Naruto is confused by Pucca's constant chasing of Garu, and he tries to help Garu escape in his own Naruto - style way.
Well, you could write a fanfiction where the Nine - Tails in Naruto has some sort of connection to a powerful entity in the Seraphim universe. This connection could lead to a series of events that require Naruto and the Seraphim characters to work together. Or perhaps a character from Seraphim is reincarnated as a ninja in the Naruto world and has to adapt to the new way of life while still having some of their Seraphim abilities.
One idea could be a blacksmith who creates unique ninja tools with special abilities that give the wielder an edge in battle. For example, a kunai that can change its shape during flight to avoid enemy defenses.