The Apocalypse Is Coming, I Built an Invincible Base Based on the System

[Apocalyptic Survival + Rebirth and Invincibility + System Flow + Base Construction + Decisive Killing] In my last life, I died in the mouth of a king-level mutant beast and was chewed alive. After rebirth, before the doomsday came, I activated - [Shelter Upgrade System]. While others are running for their lives, I am building a base. While others are starving, my farmland harvests automatically. Others were chased and bitten by alien species, but my smart machine gun tower directly beat the beasts into sieves. When my former enemy knelt down outside the base and begged me to open the door, I held a cigarette in my mouth and pointed to the sign at the door: [Conditions for entering the base: Those who have killed people are not allowed, those with evil intentions are not allowed, and those who are ugly are not allowed. [——You fucking took it all. He rushed forward with red eyes, and in the next second, 30,000 rounds of ammunition were fired simultaneously. I turned around and hugged Qingmei, looking at the beating numbers on the system panel—— [Shelter Level: LV18] [Current status: invincible] [Next stage: Counterattack around the world] Those alien species that used to eat humans are now only used as feed in my breeding farm. Is this world hopeless? It doesn't matter, I'll build one. ——If you are not convinced, come to me and give it a try.