Revelation: The Seven-Headed Dragon

Post 47 (Truth Cycle)

Then another sign appeared in heaven: and behold, a great red dragon having seven heads and ten horns, and on his heads were seven diadems. And his tail swept away a third of the stars of heaven and threw them to the earth. And the dragon stood before the woman who was about to give birth, so that when she gave birth he might devour her child. - Rev 12:3-4

The Book of Revelation has some odd passages that are difficult to decipher. This substack attempts to decipher one of the more challenging passages, a mystery of eschatology. What/who is/are the Seven-Headed Dragon?