I don't know the answer, and it doesn't matter. It is an unanswerable question. That's what the sideline debate has been about - that we can't know because the bible doesn't specifically state it. The bible gives no specificity with regard to the nature of Satan's existence. Christianity may "teach" that he was an angel, but for that they must rely on supposition.
(Which in turn comes back to the crux of the debate about abortion rights - because that charge is led largely by Christians. People who don't actually know what was said in the book of their religion shouldn't be trying to add things based on that religion into the book of laws; because what they think they know is assumption, conjecture, interpretation and what they've been told - and sometimes none of that is in the ol' bible.)
I don't care who worships what, but I don't want what they worship writing our laws at all, let alone if they're not so sure what they're worshiping, themselves.