It could be that Naruto has some sort of intel about Adaly White's weakness. He uses this knowledge to his advantage in the Gato base. He might first disable any guards or traps around Adaly White and then use his chakra - enhanced strength to land a fatal blow.
There could be a power vacuum left by Adaly White's death. This might lead to different factions in the Gato base area vying for control. Naruto may then have to deal with the aftermath and ensure that a more just leadership takes over.
In some fanfics, Naruto might use his new and powerful jutsu that he has mastered over time. Maybe he combines his Sage Mode with the power of the Nine - Tails in a unique way that Orochimaru can't counter. For example, he could use the Nine - Tails' chakra to enhance the range and power of his Sage Mode attacks, and then catch Orochimaru off - guard.
The villagers of the Land of Waves would surely support Naruto. They have suffered a great deal under Gato's rule, so they would see Naruto as their savior. Also, Sasuke might support Naruto. Even though they have their differences, Sasuke would recognize the need to stop someone as evil as Gato.
In many fanfictions, Naruto might use new jutsus or a deeper understanding of his own power. Maybe he taps into a more powerful form of the Nine - Tails' chakra and combines it with his Sage Mode in a unique way to overpower Pain.
In this kind of fanfiction, Naruto might have used his new and powerful jutsu that he developed secretly. Maybe it was a super - enhanced Rasengan with some special chakra nature added to it, which was strong enough to overpower Orochimaru.
In a 'Naruto kills Gato' fanfiction, the plot could start with Gato's continued oppression in the Land of Waves. Naruto, having witnessed the suffering of the villagers, decides he's had enough. He uses his Shadow Clone Jutsu to surround Gato and his men. With a swift combination of Rasengan and his ninja skills, he takes Gato by surprise and defeats him, thus liberating the Land of Waves in a more direct and violent way compared to the original story.
Well, in some versions, Naruto might use his new and improved Rasengan techniques. He could have combined it with his Sage Mode powers to overpower Orochimaru. Maybe he also uses his quick thinking and the element of surprise, since Orochimaru is always so full of his own schemes.
Naruto could use his improved taijutsu skills. He might close in on Gato quickly and land a series of powerful punches and kicks that Gato can't defend against. Since Naruto is quite fast and has good reflexes, he could easily overwhelm Gato in close - combat.
Well, in this fanfiction, Naruto might use his shadow clone jutsu to overwhelm the White Walkers. He could create a horde of clones and swarm them. Also, his Rasengan could be a powerful weapon against the undead. Just imagine Naruto spinning his Rasengan and blasting through a group of White Walkers.
Well, one possible plot could be that Gato has some new evil plan in the Land of Waves. Naruto, having grown stronger, decides he can't let Gato harm the innocent people there anymore. He uses his new jutsu and his quick thinking to outwit Gato's men first. Then, in a final showdown, Naruto unleashes a powerful Rasengan, directly hitting Gato and killing him, thus saving the Land of Waves from Gato's tyranny.