My Post-Apocalyptic Shelter Levels Up Infinitely!

Asdisasterwasabouttostrike,agroupofsurvivorstransmigratedintoadesolatedworldandwerechallengedtoagameofsurvival.Fromterrifyingacidrains,toendlessnaturaldisasters,theheavensburnwhiletheearthscorches,radiationisrampant,andnobodyissparedfromthedangersofthishellscape.Theonlywayonesurvivesisbybuildingashelterandslowlyupgradingitinhopesofsurvivinganotherday.Luckily,SuMoawokeaDoomsdaySurvivalSystemthatallowedhimtoinfinitelylevelupandupgradehisshelter!Themainshelterwoodendoorcanbeupgradedintoametaldoor,whichinturnupgradesintoacompositegate;thewoodenspearscanbeupgradedintobronzespears,whicheventuallyupgradeallthewayintoelectromagneticspears...Whileeveryonestruggledtosurvive,SuMowasfullyloaded,andwellequippedtodominatethepost-apocalypticworld.“Whilesomeofusarelightingoillamps,he’sbeenusingrefrigerators!”“Thewallsinhisshelteralonearetensofmetersthick,it’sthesafestplaceonthisplanet.”“BeforeIdie,Iwishtospendonedayinhisshelter...”