Another possibility is that Naruto is given an ancient artifact or power by some wise old character. This power could be directly related to controlling the Iron Sand. He then has to learn how to master this new ability, which might involve some trial and error. He could initially struggle with controlling the Iron Sand, but as the story progresses, he becomes more proficient and uses it in battles against powerful enemies.
One possibility is that he inherits it through some sort of bloodline connection that was previously unknown. Maybe there's a distant relative who had the ability to control sand, and it somehow got passed down to Naruto.
Well, it might develop as a result of some new magic he encounters. There could be an ancient spell or a magical artifact that gives him the power to control sand. He then has to figure out how to use it. He may start with simple things like making sand swirl around his hand, and as he gets more used to it, he can do more complex things like creating sand barriers or even using the sand to communicate in some way.
If Naruto can control metal sand in the fanfiction, it would be a game - changer in battles. Firstly, the metal sand's malleability allows Naruto to be extremely creative. He could shape it into complex structures, like a net to trap enemies or a large spiked ball to roll over opponents. Secondly, the density of the metal sand can be adjusted. He could make it as light as a feather for stealthy attacks or as heavy as a mountain to crush his foes. And since Naruto is known for his unpredictable fighting style, this new ability would add another layer of unpredictability, making him even more difficult to fight against.
Well, it could make his combat more versatile. He might combine sand attacks with his existing jutsu. For example, he could use sand clones in addition to his regular shadow clones. This would confuse his opponents more as they have to figure out which clone is real among different types.
He could control elements like water, which would allow him to create powerful waterfalls or form water - based defenses. Fire is also a possibility, enabling him to shoot out intense flames. Another type could be earth, where he can manipulate the ground to create barriers or traps.
The ability to control sand could be used for rescue operations. If someone is trapped under rubble or in a collapsed building, Harry could use the sand to carefully lift the debris without causing further harm. He could also use it for environmental control. For instance, if there's a drought - like situation, he could use the sand to create artificial rain clouds by using his magic on the sand's moisture content. Additionally, in battles, he could use the sand to blind his opponents by creating a sandstorm right in their faces.
In some fanfictions, it could be due to a new jutsu he discovers. Maybe during a secret training session in an ancient scroll, he finds a forbidden technique that allows him to control people.
Well, in some fanfictions, Naruto might gain the ability to control nature through intense training with a hermit or some ancient spirit. For example, he could be led to a hidden grove where the essence of nature is concentrated, and by communing with it over time, he gradually unlocks the power to control nature.
Maybe it could be through some sort of magical jutsu. Naruto is known for his unique ninjutsu skills in his own universe. He might have developed a new jutsu that allows him to connect with and control the Hulk's mind. For example, it could be a jutsu that detects and manipulates gamma radiation, which is what created the Hulk. Or perhaps he found a way to use his chakra in a new way to interface with the Hulk's rage - powered form.