Perhaps it's for exploration. Naruto is always curious about the world outside. The robots can be sent to explore dangerous or uncharted areas where it might be too risky for humans to go. They can collect information and report back to Naruto.
Maybe Naruto has some knowledge from an unexpected source. For example, he could have met a wandering inventor who taught him the basics of robotics. With his determination and quick learning ability, he then starts building the robot army. He might also use his chakra in some unique way to power or control the robots.
Perhaps in the fanfiction, the robot army is a result of some mad scientist's experiment in the Naruto universe. Naruto and his friends have to figure out the weaknesses of these robots, which could be related to chakra or some specific ninja techniques. They might also encounter some robots that can copy ninja abilities, adding more challenges to the story.
It could be Orochimaru. He's always been into strange experiments. He might create a robot army to get revenge on the village or to prove his superiority.
Maybe Naruto creates the robot army as a way to bridge the gap between the ninja villages. He uses them for peaceful purposes like construction and rescue operations at first. But then, a rogue group tries to steal the robots and use them for evil, so Naruto has to fight to protect his creation. Well, in this fanfiction, the robots could be powered by chakra, which gives them an interesting twist. They might also be able to learn ninja techniques from Naruto and the other ninjas, making them a formidable force not just in terms of brute strength but also in combat skills.
Perhaps Naruto makes the robot as a tool to help around the village. It could assist in construction, or in taking care of the elderly and the young. Since Naruto is always looking out for the well - being of his village, a robot could be a great addition.
No, it is not ethical. Naruto is a popular and often beloved character in the anime world, especially among younger audiences. Creating such inappropriate fanfiction goes against the spirit of the original work which is mainly about friendship, growth, and ninja adventures. It also involves creating non - consensual and inappropriate scenarios for a character which is unacceptable.
Sasuke might be initially suspicious. He would question Naruto's motives and the potential danger of such an army. But after seeing how Naruto uses it for good, he might come to accept it.
The idea of a character being a one - man army is exciting. In Naruto, we usually see him with his friends. But in this type of fanfiction, it's all about his individual strength. It gives a fresh perspective on his character.
At first, Naruto might be a bit cautious. He's used to facing opponents in battle, and a strange new object like a robot could potentially be dangerous. But once he realizes it's not an immediate threat, he'd likely approach it with his usual enthusiasm. He might start asking it all sorts of questions, like 'What are you?' and 'Where are you from?' His reaction would be a mix of excitement and wariness.