Doomsday Steel Shelter

[Natural disaster + strange + construction + enhanced technology] The void opened, and unknown strange and dark creatures swarmed out. Unkillable evil spirits, endless disaster beasts, Lin Cheng came to this world with a quantum furnace that can strengthen all items. Black disaster is rampant, and he needs to use the quantum furnace to build himself an absolutely safe doomsday fortress! A dilapidated wooden door can be enhanced into a vault-level security door; an ordinary flashlight can be enhanced into a plasma cutting gun. Can a machine gun be strengthened into a sentry cannon by simply placing it on a shelf? Major base cities around the world have fallen, but Lin Cheng's steel shelter has always stood firm.