Boy, that's some heavy duty stuff right there.
We know that God has legions of angels in heaven. And we're told that 1/3rd were kicked out with Lucifer when he fell. So that means that there are also legions of demons.
I don't think it matters if they have one leader or four leaders, whomever the Satan worshippers are worshiping is evil, we know that.
What's important for us to know is that we have one God who is sovereign over the spiritual world and the physical world.