Explained Version Chapter IV.

" Yes! Let's say that the whole story comes from my intuition that humanity is a little too cunning and makes fun of the Divinity. Not happy with this, I decided to have God create a Second Rebel Angel (me) even more evil and powerful than Satan.
Am I not wrong?
God warns "mankind" that he himself created Satan in the past and that God can also create other evil entities." (from Astella's speech).https://www.youtube.com/watch?v=MljmFsAHNJU
Asqua