An army of literal demons marched straight out of Hell, trampling over the survivors wherever they found them. When they killed, they wore their victims' skins. When they conquered, they seized their enemies' weapons. Powered by supernatural evil and loaded with military hardware, they scattered us and ran us down.
But then she came. At first, we thought she was one of them — a woman in black, with a long gun like a witch's broom and the magical powers to match. Survivors whispered her stories in the alleyways: stories of battles so intense that they leveled whole city blocks, during which she mowed down entire demon regiments with flaming bullets, then shared her own blood to save the wounded. They say she can summon clouds of ravens, call up thorns from the ground, and even conjure up lightning and tornadoes at will.
Maybe she flew down from Heaven. Maybe Hell spat her back out. Either way, she's all we've got.