Skeleton Knight, in Another World - Chapter 21Volume 5 -

In the tenth year after the new era, the world finally came to an end. Zhang Mu truefully waited for his death, but unexpectedly found that he had returned to ten years ago. With his memory about the future, he swore that he would change the calamitous history, saving the earth from being destroyed! Walking dead, zergs, evolvers, and various mutated animals… nothing can stop him! The first step is to retrieve his identity as an era merchant , then find all the treasures he can remember to enhance himself!

- Description from Novelupdates

DING!![You killed a Level 3 Mutant Zombie for the first time!]-----DING!![You have crossed the limit of humanity! Entering the mutation stage!]-----DING!![Congratulations, user! You are now a being beyond human beings!]-----Being a good person cost him his life. When death sent him back, he vowed to take revenge and finish the job.Behind the icy cold that grips the world and the red light that fills the sky day and night, he must defy the zombie apocalypse.A safe house, unlimited food and drink, every conceivable weapon and a system to help him... But he has only two things on his mind: Survival and revenge.

System Notification: Your King of Passivity talent was activated through killing the Elit Demon Clan Warrior. You have automatically received the Critical Strike (Passive) Skill.

What? I got another passive skill.

I have way too many skills, I can barely see the end of my skills panel.

I need to be low-key, low-key.

This is the story of a game grinder who used his passive skills to destroy legends.