Time Travel Zombie Game: Doomsday Upgrade System

Traveling to the end of the world, a game world where zombies are rampant, I wanted to kill everyone, but because the balance of the world was overturned, I started from scratch, with dangers and hidden murderous intentions. I also encountered national rebellions and a surge of zombies. I finally integrated with the game. I upgraded my powerful proficiency to kill monsters, fought with NPCs through life and death, and as a world leader, led NPCs to fight the boss, and finally became the overlord. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.