8 Utterly Mind-Blowing Dark Souls Trilogy Fan Theories

In Demon's Souls, the world is gradually enshrouded by a deep fog, which cuts off the kingdom of Boletaria from the outside world. Though neighbouring kingdoms send scouts and warriors to investigate this fog, none return after entering it. The spread of the fog is associated with the awaking of the Old One, a great demon residing below a hub called the Nexus.

This theory postulates that the ending in which the player does not return the Old One to slumber is canon, and over time the world is completely covered in a grey mist. The demons take over, killing everything in their path except for the dragons, who are simply too powerful to be felled. Eventually, the dragons begin to kill the demons, and the Old One dies.

Ages pass, and eventually the Archstones from Demon's Souls hatch like seeds, causing Dark Souls' “arch trees” to sprout. The world is now nothing but trees, dragons and mist, just like the Age Of Ancients.

Finally, from the Old One's corpse comes a flicker of life, a spark that causes the development of the First Flame. It's a startlingly seamless transition!