Doomsday Sign-In for 365 Days

I bound the doomsday sign-in system, which rewards a safe house on the first day and unlimited food on the second day. Just when I thought I was the chosen one, the system sent me a new task: [Please survive in the core of the zombie lair for 24 hours] I later learned that all rewards came from the legacies of the first 72 hosts. And their corpses were looking at me from the depths of the lair.