From Abyssal Invasion to Bursting Stars with a Single Sword - Chapter 280 - 228: Teleportation, Darkville Black Iron Tribe

Caution: This novel contains R18 content. Doomsday had arrived overnight. Zombies roamed every corner and humanity had suffered a massive setback.

Between heaven and earth lies the greatest truth, and the manifestation of the great truth descends in the form of Gu.　　People cultivate the Qi of heaven and earth around their bodies to control Gu and exert their magical power.　　One year after his transmigration, Chen Qing finally discovered his special features on the day he contracted his first Gu. He was actually able to see through everything about the Gu...　　Therefore, he began to march toward the road to immortality step by step.

Perhaps it is the choice of fate. As a senior otaku, Qian Lingfeng got the “steel shell system”. However, when he swept the world with the system, became a local rich man, made all kinds of beautiful women, opened a harem, and realized the ultimate fantasy of thousands of otaku, he found that things seemed far from simple!
When the end comes, biochemical zombies suddenly come down, fierce beasts are in power, bloodthirsty zerg roam to kill the world, and human lives are comparable to dirt. Where will weak human beings go in this world? Is humanity going to be extinct? Or … can an otaku save the fate of the human race?

- Description from Novelupdates

I became a mage character from my favorite game.