In this fanfiction scenario, the outcome might also be a draw. Maybe they both reach a point where they realize they are evenly matched. Naruto's strength and Neji's precision could cancel each other out. They might then come to an understanding and end the fight without a clear victor, which could also lead to a new friendship or alliance between them in the context of the fanfiction.
The plot could start with a tournament - like scenario where Naruto and Neji are pitted against each other. Naruto is tired of Neji's overconfidence and decides to teach him a lesson. So he goes all out from the start and uses his unique ninja skills to overwhelm Neji.
Naruto. He's known for his unorthodox fighting style. When he goes all out, he might pull out some really unexpected moves. For example, he could combine his shadow clones with a new type of Rasengan variation that Neji has never seen before.
In such a fanfiction, Naruto and Sasuke might win. They are both extremely powerful and their combined strength, like Naruto's Rasengan and Sasuke's Chidori, could overpower Madara.
The outcome in this fanfiction could be a draw. Naruto and Hinata would put up a great fight against Pain. Naruto would be all fired up, using his Rasengan and other ninjutsu. Hinata would be there, protecting Naruto's blind spots with her gentle fist techniques. But Pain is no pushover. His ability to control gravity and rain down destruction could keep Naruto and Hinata at bay, leading to a situation where neither side can fully defeat the other.
He could meet female versions of his existing friends like a female Sasuke or Sakura. They might have different personalities while still retaining some of the traits of their male counterparts. For example, a female Sasuke could be just as strong - willed but with a more feminine touch in her fighting style.
In the 'naruto goes on a rampage fanfiction', it could be that Naruto is under some sort of dark magic or mind - control. This makes him lose his usual self - control and go on a rampage. He could start attacking both enemies and allies without realizing it until someone finds a way to break the spell on him.
One possible plot could be that Naruto is constantly ostracized by the villagers even after all he has done for them. The years of being treated as an outcast and having his good intentions misconstrued finally push him over the edge. He starts to see the villagers as the real enemy and decides to use his power not for their protection but to make them feel the pain he has endured.
One possible motive could be a dark or alternate universe take. Maybe in this fanfic's world, there is some sort of dark magic or mind control that forces Naruto to do it against his will.
Well, one possible theme could be the challenges of the unexpected pregnancy in a world where male pregnancy is not the norm. It could explore how Naruto and Neji deal with the social stigma and their own personal feelings about the situation.
He might end up in a really bad state of health. Drinking more beer when already the drunkest can lead to alcohol poisoning, which is extremely dangerous.