Five years after the outbreak of the "Great Annihilation" event (unknown cosmic radiation + extreme climate superposition), more than 90% of the earth's land was covered by toxic sandstorms, fresh water resources were depleted, and vegetation died in large numbers. Some organisms mutated due to radiation (strongly aggressive but not intelligent, such as "Sand Locusts" and "Rotten Wolves"). The human survivors were less than 1% before the war, scattered in a few "oasis settlements"
