Antichrist ought to be understood as a false, substitute, and adversary messiah first, and understood in part as before, but not as the Antichrist will be (falsely) presented as the first and original Messiah.
Antichrist(s) are spurious counterfeit spirit(s) created by fallen angels: “And every spirit that confesseth not that Jesus Christ is come in the flesh is not of God: and this is that spirit of antichrist, whereof ye have heard that it should come; and even now already is it in the world.” (1 John 4:3). Of/ek in “not of God” is defined as the point of origin. It follows that if the spirit of antichrist does not originate with God, then those spirits are demonic, disembodied spurious offspring of fallen angels that were in the world at the time of John and before. Antichrist spirits are liars that deny Jesus is the Christ and deny both the Father and the Son, demonic spirits that remain at work until the true Antichrist is revealed with his crowning in the temple. The antichrist spirit is not fallen angelic spirit but one should anticipate that the avatara Antichrist will have a fallen angelic avatar supplying his powers, perhaps a demonic avatar. It follows that Antichrist will in part will be from “before,” as with the incarnation into Antichrist of the spirit of the Antichrist, perhaps a Nimrod or antediluvian giant, and an incarnation of an angelic avatar spirit known as the christo/christ consciousness in polytheism.
Antichrist will be a spiritual chimera beast, a creature who denies the Father and Son in his ignorance, arrogance, temerity, and hubris. Fallen angels utilize humans, Nephilim, Rephaim, and disembodied demonic spirits of the latter two to slander loyal angels, God, Jesus, and the Holy Spirit, because fallen angels know the power of God Most High. The psalmist says, “So foolish was I, and ignorant: I was as a beast before thee.”