Maybe it has some special chakra storage or amplification abilities. For example, it can store extra chakra for Naruto to use in emergency situations, or it can amplify the chakra he sends through it for more powerful attacks like Rasengan.
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.
In the fanfiction, the fake arm might have the ability to transform. It could change its shape to fit different needs, such as becoming a shield to protect Naruto from attacks or morphing into a tool like a grappling hook to help him reach high places or catch enemies from a distance.
One special ability could be enhanced strength. The metal arm might be able to deliver much more powerful punches than his normal arm, allowing him to break through tough defenses more easily.
Well, in some fanfictions, he might get it from a skilled ninja prosthetics maker. This maker could be someone who specializes in creating artificial limbs for ninjas who have lost their arms in battle.
One common theme is adaptation. Naruto has to adapt to having a fake arm, whether it's in combat, training, or daily life. Another theme is often power - up. The fake arm might give him new abilities or enhance his existing ones. For example, it could be a super - strong arm made of some rare material that lets him punch through walls or something.
One interesting Naruto fake arm fanfiction could be one where Naruto gets a special prosthetic arm after a battle. It might have unique abilities, like being able to channel chakra in new ways. Maybe it was crafted by a hidden master. Another could focus on how he adjusts to having a fake arm in his daily ninja life, dealing with tasks that were once easy but now are a challenge.
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.
One possible fanfiction could be about Naruto's right arm gaining a new and mysterious power. Maybe it starts to glow with an unknown chakra, and he has to figure out how to control it without losing himself. It could be a power that has a connection to an ancient ninja clan's secret technique.
His right arm could get a cool tattoo that gives him extra powers. For instance, a tattoo that allows him to summon a special type of animal or use a unique jutsu.
Sasuke could be a candidate. Given their complex relationship, Sasuke might find a way to give Naruto a new arm as a way to atone for their past differences. He could have discovered some rare medical ninjutsu during his travels or come across a powerful artifact that he uses to create a new arm for Naruto.
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.
Well, losing an arm would definitely have a huge impact on his ninja abilities. His ability to perform hand seals would be severely hampered. For example, complex jutsus that require multiple and quick hand seals might become impossible for him to execute. Also, his balance in combat could be affected as he's used to having two arms for movement and defense. He'd probably have to rely more on his legs and other non - arm - related skills.