Board Thread:Lore Discussion/@comment-4511886-20150329140746/@comment-25108056-20150330163631

I believe it was Gwyn rekindling the First Flame, as he broke the natural course of life by doing it, starting an artificial cycle of Light and Dark, and the human beings were the ones who had to pay for it. But I have also read some theories affirming that the first sin could be the attempt to recreate the First Flame by the Witch of Izalith, since there are some facts in the game that connects Aldia with her. First, because his appearance resembles that of the Bed of Chaos, and second because we can see a couple of Enhanced Undead, which are a creation of Aldia, in Sinner's Rise - the same place we can find the Lost Sinner, who is known to posses the soul of the Witch, and, according to Shalquoir, was trying to light the First Flame.