Well, in some fanfictions, it could be due to a new jutsu he discovers accidentally. Maybe during a really intense training session in a mysterious place, he unlocks this strange power.
Another possibility is that it has something to do with his connection to the Nine - Tails. Since the Nine - Tails is such a powerful and otherworldly force within him, some sort of energy transfer or mutation might occur that gives Naruto the ability to phase through objects. This could be related to the Nine - Tails' own nature of being able to exist in a different dimension or state at times.
It might be the result of a curse or a blessing from some ancient entity. For example, he could have come across an old shrine in a forest and unknowingly received this power as a form of protection or test from a long - forgotten spirit.
One implication is that he can easily avoid attacks. Enemies' punches and weapons would just go through him, giving him a huge advantage in combat.
Maybe he discovers a special jutsu scroll left by an ancient sage. This scroll contains the secrets of dimensional travel that no one has been able to decipher until Naruto, with his unique determination and connection to the chakra of the world, figures it out.
Well, sometimes in fanfics, authors like to come up with new powers for characters to make the story more exciting. So Naruto pulling objects out of nowhere could be a way to add an element of surprise and mystery to the plot.
Perhaps in the 'naruto can phase fanfic', the plot could also involve Naruto using his phase ability for more than just combat. He could use it to solve mysteries in the village, like finding hidden passages or uncovering secrets. This might put him in the middle of some political intrigue in the Hidden Leaf Village as well. And as he delves deeper into using his power, he uncovers a larger conspiracy that he has to stop, all while still dealing with his normal ninja duties.
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.
In some fanfictions, Naruto might gain the ability to summon zombies through dark magic or a forbidden jutsu he discovers. Maybe he stumbles upon an ancient scroll that teaches him this unorthodox summoning technique.
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.
Well, in some fanfictions, it could be due to a special encounter. Maybe he meets a powerful dragon spirit during one of his adventures. This spirit, seeing Naruto's potential and kind heart, bestows upon him the power to transform into a dragon.
Another possibility is that Naruto acquires the ability to control the weather from a powerful artifact. He might stumble upon an ancient relic during one of his adventures. This artifact has the power to control the weather, and once Naruto touches it or figures out how to use it, he gains this extraordinary ability. It could be that the artifact was created by a long - forgotten civilization that had mastered the art of weather manipulation.