Doomsday: Let You Save the World, You Build the Palace into a Wall

[Zombie + ancient + fictional + not invincible] In the third year of the Yuanhe period of the Great Wei Dynasty, corpse plague broke out and the world was in chaos. The peerless swordsman used his sword to kill the fourteen states, but he became a corpse king because he didn't know the rule of "scratch is death". The eminent monk of Vajra Temple tried to chant sutras to save the group of corpses, but was chewed up until only his skeleton was left. In this world, I, Li Gou, am just a useless bastard with no inner strength. But I know that they can hear sounds, smell blood, and - they must shoot their heads! Others are practicing martial arts, while I am hoarding rice... Hoarding lime and spears. While others were defending the city to the death, I was digging tunnels, setting up barriers, and making Molotov cocktails. "Li Gou is a coward who never steps out of the door!" Until that day, millions of corpses surrounded the city, and warriors all over the city howled in despair. Only my "Gou's Castle", with spears like a forest and fire oil like rain, cuts a bloody path! Savior? No, I'm just simply afraid of death.