The NPC sets out to defeat the demon king - Chapter 25

There are always four kinds of people in the traditional Mary Sue world. The Male Lead, the Mary Sue female lead, the woman who never wanted to see the female protagonist live a good life, and the infatuated man willing to destroy heaven and earth to get the female lead.

Hagoromo Gensou transmigrated to the Naruto world and, through his own efforts, became a prominent figure in the ninja world.Until one day, the newly appointed Five Kage teamed up and ambushed him immorally. It was only then that the system finally appeared, claiming it could help him rise to become the strongest in the ninja world.However...Just as he was about to confront the Five Kage head-on, Gensou silently looked at the first task issued by the system.[Quest: Ninja School Comeback Initiated! Please defeat your dead-last classmate, Uzumaki Naruto.]“System, do you know what year it is now?”[Year 60 of Konoha]“Right now, it's Year 2 of Konoha! Is there something wrong with this system?!”...Many years later, Gensou opened his eyes again, standing on the rooftop of the Chunin Exams building. Looking at the Third Hokage, who was ready for battle, he smirked slightly:“Although it's a few decades early, I finally made it.”[Raw: 火影：我都硬刚五影了，系统才来]

Living things really are ignorant – the greed to obtain the key to knowledge and the fundamentals of energy overpowers them. Little do they know that knowledge is full of lies and energy is the root of destruction. Us, mages, have mastered travelling through space and time. We are invincible, we can turn worlds into dust and you, mere ants, will be wiped out with no trace.

-Mage Adam

An A.I.(Artificial Intelligence) gets reincarnated into a world where he becomes a mage.