Armageddon has overturned the world's destiny, where an Evil God has risen after gaining power from the ego of humans who feared death. As a result, eight billion people were sacrificed, leaving only a handful of survivors to exist merely as playthings for the god in a world shrouded in eternal darkness. In this twisted world where logic is gone, human blood has become everything—from currency and fuel to a forbidden weapon forged by sorcerers to eradicate demons. Eva and Epica are a pair of sisters bound by a tragic fate in the midst of this apocalypse. The younger sister, Epica, is the ultimate blood-battle human who has lost her soul, while the older sister, Eva, was born unable to walk. However, only Eva's blood can awaken Epica's power to fight against the demons that have defiled the world.