A possible storyline is that Naruto is transported to a parallel dimension where all ninjas have elemental powers from birth. There, he is initially at a disadvantage because he doesn't know how to use his new - found fire control. But with the help of some friendly locals, he starts to master it and eventually uses it to fight against an evil dictator in that dimension who is trying to take over all the ninja clans. Another storyline could be that Naruto's fire control is tied to his emotions. So, when he gets angry, the fire becomes uncontrollable. He has to learn emotional control along with mastering the power to use it effectively in battle and in his daily ninja life.
Well, Naruto's control over physics could completely turn the plot upside down. He could use it to create new jutsus that defy normal physical laws. For example, he might be able to make objects move without any force being visibly applied, which could give him an edge in battles. This new power would also make his enemies have to re - evaluate their strategies against him.
Well, it could make his combat style more aggressive. He might start using more direct, offensive moves. For example, he could send out waves of fire towards his opponents, forcing them to constantly be on the defensive. Also, he could combine his fire control with his existing ninja skills, like the Shadow Clone Jutsu. The clones could surround the enemy and then all release fire at once, creating a sort of inescapable ring of fire.
Naruto could develop his water control abilities through intense meditation. By focusing his chakra and mind, he can better understand the nature of water. He may also study the movements of water in nature, such as how rivers flow and how water droplets form. This knowledge would then be applied to his jutsu, gradually improving his control.
Maybe it could be due to some dark jutsu he discovers accidentally. For example, he might find an ancient scroll in a hidden cave that details the method of controlling corpses. This could be a jutsu forgotten by time, and Naruto, being the curious and determined ninja he is, decides to study it.
One possible ability is the control of entropy. Naruto could reverse the decay or disorder of things. He could repair broken objects or even heal wounds by reversing the natural process of damage. Also, he could control electromagnetic fields. This would allow him to disrupt enemy electronics if there were any in the Naruto world, or he could use it to attract or repel metal objects.
Well, it could completely reshape the battles. Instead of relying on just one or two main elements like wind in the original, he can now use a combination of all elements to outwit his opponents. For example, he could use water to douse an enemy's fire jutsu and then follow up with earth to trap them.
In fanfiction, Naruto could potentially control a wide variety of animals. For example, he could control small and nimble animals like squirrels. Squirrels are quick and resourceful, which could be useful in various situations. He may also have control over larger animals such as bears. Bears are strong and intimidating, and Naruto could use their strength for protection or combat. Another possibility is that he can control dolphins if the story involves water - related scenarios. Dolphins are intelligent and friendly, and they could help Naruto in underwater missions or just be his companions in a more aquatic - themed fanfiction.
One interesting application is his ability to create entirely new jutsus by combining different elements. For instance, he could mix fire and wind to create a super - heated blast that's more powerful than either element alone.
One possibility in this fanfiction is that Naruto is exposed to a powerful and otherworldly energy source. This energy could be from a different dimension or a long - forgotten relic. When he comes into contact with it, his body absorbs and adapts to it in a way that allows him to control black fire. This new power also comes with its own set of challenges and responsibilities for Naruto as he tries to integrate it into his existing set of skills.