Doomsday: My Fortress Can Be Upgraded Without Limit

For ten years in the apocalypse, my brother and girlfriend joined forces to betray me, and I died in the shelter I had built myself! Reborn overnight, I return to one month before the countdown to doomsday! Looking at the two billion in my bank account, I smile. You want my supplies, don’t you? Fine! This time, I’ll stockpile supplies worth tens of billions and build an impregnable steel fortress! When the endless night falls and you’re wailing in despair in the seventy-below-zero cold, I’ll be inside my fortress, eating hotpot and singing. As for that treacherous couple? Don’t rush. The game has only just begun!