User blog comment:Fallen Great Grey Wolf Sif/Concerning Question About Dark Souls Morales./@comment-68.97.244.204-20140515033306/@comment-16047389-20140516173121

It's not really "post apocolyptic". Lordran wasn't devastated by a plague, or an explostion, or a cataclysmic event. The Flame was dying, so most of the gods left, and things fell apart.