Maou-sama no Machizukuri! ~Saikyou no Danjon wa Kindai Toshi~ - Volume 2 Chapter 8

At dawn.The light of dawn lingered, hesitant to arrive, while the remnants of the setting sun had long faded into darkness. Within the city shrouded in thin mist, the hidden churches in the shadows, veins clinging to the cracks in walls, the gnawing sounds echoing from the sewers, and the murmuring shadows...A lantern bearer strolled forward.

Li Yi accidentally obtained a black science and technology library, which contains countless books of the inheritance of high-tech civilization and records countless knowledge.

There are thousands of bells in the book, there is a golden house in the book, there are many horses in the book, and there are Yan Ruyu in the book.

Li Yi has completely turned into a bookworm, learning all kinds of knowledge from the library, grand unified theory, particle Tebo theory, …, acquiring various black technologies, superconducting materials, super batteries, intelligent algorithms, … .

- Description from novelbuddy

When I cleared the final chapter of a game that was a national failure, I became an unnamed side character in it.

A non-standard, unmeasurable, EX rank supporting character.

Earth Immortals are cultivated from a blessed land.