The writer of Revelation says: "there was war in heaven".
My understanding of grammar is that as far as the 1st century writer was concerned, this had already happened in the past. He does not write: "I saw that there is going to be a war in heaven". For him, it had already taken place - Satan was already on earth.
Who was the "woman clothed with the sun, with the moon under her feet"? Someone who gave birth to a son who was snatched up to God and his throne. Did he possibly mean that the woman was the nation of Israel? Certainly he was not speaking of a literal person.
Where was the desert she went to for 1260 days, after she obtained eagle's wings?
And Satan has seven heads as well as horns and crowns? If he was around, he certainly would make the TV news bulletins in Australia, I am sure.
Let's be real about this fanciful imagery and never build a belief based on it!
Doug