Blood Shaper - Chapter 20Book 6:

What if something made Naruto the dead-last that everyone perceives him to be? What if he really wasn't as weak as he appeared? The true Naruto, unleashed upon the shinobi world! AU story starts at the Konoha Invasion arc and continues from there..

He was on his way to buy some beer to celebrate his acceptance as a civil servant when he was suddenly isekai’d by truck-kun.

The Spirit Network, known as【Deep Sea】 connected five continents as human civilization surged forward; yet, they were oblivious to the impending eternal night. With the Extraordinary Awakening, the edifice was about to collapse. Flesh is weak and pitiful, how could one ascend? The story began when Gu Shen, an ordinary youth, received a ruler that bore the truth. He peeled back the corner of this extraordinary world, becoming the largest moth among the thousands that dashed into the flames. If winter is coming, I will climb against the steps, overturn the thrones of kings, shatter the crowns of falsehood, destroy the scepters of injustice. I will become humanity's last, Bright Barrier.

In a certain world, there was someone who excelled in magic combat, people called him 『Sage』. Seeking the strongest combat art, he devoted himself to research every magic and combat arts in existence. And the conclusion he arrived at was very cruel, 『My body is not fit for magic combat』. Yet he didn’t give up. He sealed his own soul with a magic art, and was reborn in a far-off future. And the magic theory in the completely changed world he saw there was of unbelievably low level.