What are the special abilities of Naruto's metal arm in the 'Naruto has a metal arm' fanfiction?

Well, it could be that he got it as a gift from some super - advanced ninja technology group in the fanfiction world. Maybe they saw his need for an extra weapon or tool during battles and decided to equip him with a metal arm.

Yes, there might be. The Harry Potter fandom is vast and diverse, and fans often come up with creative and unique concepts like this for their fanfictions. There could be a writer who decided to give Harry Potter a metal arm in their story for various reasons, perhaps as a result of a battle injury or some magical - mechanical experiment gone wrong.

The weird arm might enhance Naruto's physical strength. For instance, he could be able to lift much heavier objects or deliver more powerful punches.

It could have enhanced strength. Since Naruto is already quite strong, the fake arm might be designed in the fanfiction to multiply his physical power, allowing him to punch even harder or hold heavier objects.

One possible plot could be that Harry gets his metal arm during a battle with Death Eaters. The arm could be magically enhanced, with runes inscribed on it that give him new abilities like being able to sense dark magic from a distance. He then has to learn to control these new powers while also dealing with the prejudice from some in the wizarding world who see his metal arm as something 'unnatural' in a magical setting.

His metal arm could come from a cursed object that backfired on him. For example, he might have been trying to disarm a powerful dark magic item and it ended up fusing with his arm, turning it into metal. This would then force him to learn how to control the new power within the metal arm.

Well, his metal skin could enhance his defense greatly. Enemies' attacks like kunai stabs or basic jutsu blasts might be deflected or absorbed more easily. It could also add weight to his punches, making his physical attacks more powerful.

Fanfic often explores the idea of Bucky's metal arm sensitivity in relation to his overall state of mind. If he's in a stressed or emotional state, the arm might become more sensitive, almost like it's reacting to his internal turmoil. Writers may use this to show his vulnerability. For instance, when he's having flashbacks of his past traumas, the metal arm could tingle or ache, emphasizing the connection between his mental and physical state.

Maybe it was the result of some experimental jutsu gone wrong. Or perhaps he was exposed to a special kind of metal - based chakra.

Naruto may become more cautious. With a prosthetic arm, he realizes his vulnerability more. He might start to think more strategically before jumping into battles. For example, in a fight, he won't just rely on his brute strength but use the unique features of his prosthetic arm to his advantage.