[No System + Apocalypse + Not a self-sacrificing saint + Ordinary person + Decisive but still humane + Character growth] The early pacing really is a little slow, but it gets much better around a dozen chapters later. You can try skipping ahead. Comments are welcome.
After much effort, Earth finally found peace. The world’s nuclear weapons and artillery shells were collected and destroyed in great numbers, and war became a thing of the past. Everything was moving in a promising direction. But then a drug called Alpha, made from extraterrestrial material, brought an unprecedented disaster. People turned into bloodthirsty monsters, and even plants began to go mad. Without heavy weapons, humanity was powerless to resist. Faced with a tide of zombies, can Yi Ang, a college student, survive...?