Well, the Naruto vs Pain fight in the original series is epic. Fanfiction allows fans to explore different scenarios and what - ifs. Maybe they want to see different character developments during that intense battle.
In the original Naruto vs Pain fight, there were many unanswered questions. Fanfiction tries to answer those. For example, what if Naruto had more help? Or what if Pain had different motives? This makes it appealing to fans who want to explore these ideas.
I'm not sure specifically about a story named 'everyone vs mimi imfurst'. It could be something very specific within a certain community or context that I'm not familiar with.
One consequence could be an imbalance in the world's population. There might be too many people for the existing resources, leading to shortages of food, water, and living space.
It could be that his new 'godlike' power has isolated him. People might be either in awe or afraid of him, and he may feel that he can't be close to others as before. So he acts coldly as a defense mechanism.
Well, in some fanfictions, Naruto might use some super powerful jutsu that he either discovers or creates. Maybe it's a new form of the Rasengan combined with some sealing techniques. It could also be that he taps into some ancient power or makes a deal with some sort of god - like entity within the Naruto universe.
Maybe he got some kind of curse. In the Naruto universe, there are all sorts of dark magic and curses. If he was cursed, it could make him withdrawn and cause him to ignore everyone.
One possible reason could be a powerful genjutsu cast over the village. Maybe an enemy ninja with strong illusionary powers managed to make everyone forget Naruto. It could also be due to some sort of curse. For example, a dark curse was placed on Naruto that made people's memories of him fade away gradually.
One possible reason could be that Naruto has seen or experienced something that makes him distrust or fear those around him. Maybe he has discovered a dark secret about the village or his friends that has shaken his beliefs.
It could also be that Naruto has had some sort of revelation about himself or the ninja world. He might have realized that the relationships he has been in were holding him back in some way. Maybe he wants to focus on self - improvement and growth, and he believes that being alone is the best way to do that. He could be trying to find his true self without the influence of others.