Thread:LiveandSound/@comment-25405817-20150312002546/@comment-25555436-20150312135926

Regarding Demons in Persona, I found this:

"In the Persona universe, Gods and Demons exist within the Universal Unconsciousness, which exists due to the Star Eater's influence. To resist it's wave-like psyche, after it's body became the moon, and stood as a contradiction to themselves, Earth's primitive life evolved a universal unconsciousness and the Gods and Demons within it. Gods and Demons emerge from humans as a way of defending their psyches from the Star Eater.

Humans can also turn into Demons if their psyche is destroyed, or if they are artificially given a new Persona after having theirs forcibly removed, especially if the extracted Persona was artificially granted too" 

And before you ask, the Star Eater is Nyx.