Revelation 12:3 refers to Lucifer/Satan in his true, dragon form (Revelation 12:9, Revelation 20:2). Lucifer and his angels will be cast down out of heaven to the earth for good mid-tribulation, after losing a war in heaven (Revelation 12:7-9). But instead of coming down as a defeated force, they could descend for all the world to see in beautiful, gleaming spaceships onto the "Champ de Mars" (Mars being the same as Marduk, the chief god of ancient Babylon), the large open area in front of the Eiffel Tower in Paris. And Lucifer, a literal, seven-headed dragon (Revelation 12:3) could emerge in great splendor and command his legions of angels to destroy all of the 200,000,000 weird horse-like creatures (which the world could see as "aliens") which will have been slaughtering a third of mankind (Revelation 9:17-18). Lucifer could say that he has come to rescue mankind because the Antichrist, who he could say is his only-begotten "Son", was able to send out a mental distress call to his "Father" Lucifer in heaven to come to the rescue with his legions of angels (like an Antichrist counterfeit of Matthew 26:53: "Thinkest thou that I cannot now pray to my Father, and he shall presently give me more than twelve legions of angels?"). Lucifer and the Antichrist could then be received by the world as the saviors of mankind.
The world could at first see the dragon Lucifer and his angels as merely different aliens, more powerful than the horse-like aliens. The world could think that Lucifer and his angels are (in the world's words) "come to visit the earth and help mankind to survive this awful tribulation. They will bring us to the next level of scientific advancement and to the next level of spiritual enlightenment". The New Agers could even welcome them with open arms as the "Ascended Masters" come in person to bring mankind into "the New Age". Lucifer and his angels themselves could explain to the world that they aren't aliens in the sense of material beings from somewhere else in the galaxy, but are a higher order of (in their words) "wholly-beneficent" spiritual beings come from the third-heaven spiritual realm (outside of the material universe) to rescue mankind.
Lucifer and the Antichrist, along with the miracle-working False Prophet of the Antichrist, will then deceive the world into actually worshipping Lucifer (the dragon) and the Antichrist (the beast), and an image of the Antichrist (Revelation 13:4-16, Revelation 19:20, 2 Thessalonians 2:4, Daniel 11:36). And everyone will be made to receive a mark of the Antichrist on their right hand or forehead, consisting of the name of the Antichrist or the number of his name (Revelation 13:16-18). The Antichrist will turn the world against YHWH, the God of the Bible, speaking terrible things against him (Revelation 13:6, Daniel 11:36). The Antichrist could lie and say that it was YHWH who sent against mankind the awful alien creatures (and all the preceding, natural disasters of the tribulation: Revelation 6:12-14, Revelation 8:7-12), when in fact it could be Lucifer and his fallen angels who did all of that from behind the scenes, so that they could subsequently arrive on the world stage as if they were the good guys come to rescue mankind.
They could promise mankind that they will help mankind to defeat YHWH and to escape (what they could call) "YHWH's vile prisonhouse of this material universe, and return to the heavenly, spiritual realm of bliss, the Pleroma, where mankind existed in pure-spirit form from all eternity, before by some mishap mankind fell into YHWH's trap and became enmeshed in the material realm". This lie is what Gnosticism teaches. The Antichrist will be Gnostic, for he will revile YHWH (Revelation 13:6, Daniel 11:36) and deny that Christ is flesh (1 John 4:3). The Antichrist will at the same time also be Luciferian, for he will bring the world into the worship of Lucifer (Satan) the dragon (Revelation 13:4). The Antichrist could present him to the world as (in his words) "Our Lord Lucifer, the Savior of mankind. He will free us from YHWH's tyranny and lead us back into the Pleroma to live in bliss forever".
After Lucifer and the Antichrist have completely deceived the world and ruled it ruthlessly for 42 months (Revelation 13:4-18), YHWH will send his vials of wrath against the unsaved world (Revelation 16). Those in the church who will still be alive on the earth at the time of the vials (Revelation 16:15) will go into protective chambers which they will have built for themselves on the earth (Isaiah 26:20), just as Noah and his family went into the protective ark which they had built for themselves on the earth (Genesis 7:7). Near the end of the vials of wrath, unclean spirits like frogs will come out of the mouths of Lucifer (the dragon), the Antichrist (the beast), and the False Prophet (Revelation 16:13), and these unclean spirits like frogs will go forth and perform amazing miracles to convince all the armies of the world to gather together at Armageddon (Har Megiddo: Mount Megiddo in northern Israel) (Revelation 16:16) in an attempt to fight and defeat YHWH himself (Revelation 16:14, Revelation 19:19). After gathering together at Armageddon, all the armies will then travel south and defeat Jerusalem, right before Jesus (who is YHWH, John 10:30), returns from heaven and defeats them (Zechariah 14:2-15, Revelation 19:21). Jesus will at that time also defeat the Antichrist himself and the False Prophet (Revelation 19:20), and will have Lucifer bound in the bottomless pit for 1,000 years (Revelation 20:1-3).