In the End of the World, I Can Upgrade Items Infinitely

In the last days, everyone is struggling to survive in endless crises I upgraded my three-bedroom apartment into a fortress, and I can collect as many monsters as they want. I upgraded the kitchen knife into an indestructible tiger sword. The monster can destroy a building with one blow, and the monster can withstand nuclear bombs... I am just like chopping melons and vegetables. I upgraded my coat to a basalt sapphire fairy coat with a defense bonus of 100 million. The missile landed on my head. Well, I have to fix my hair again. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.