So, my feelings are that Antichrist will present as an "alien". We're being predictively programmed by accept the notion of aliens.
What would feel nearly the entire world? If some guy came saying he's the second coming of Mohammed, most Christians would scoff at that, of even if Christ, Muslims and Jews would scoff at that.
Let's say some "alien" shows up and then shape-shifts to look like Christ, Moses, Mohammed, etc. and tells the world that those great religious figure were really aliens ... and then replicates the miracles performed by Our Lord, Moses ... and whatever Mohammed did. Evidently the last miracle AntiChrist will attempt to perform will be to ascend into Heaven, and that's when he's struck down by God.
99% of everyone on earth would fall for it and lose whatever faith or "faith" that they had, and would buy into the alien deception.
That's also why I believe they invented the round earth and space deceptions, since, if you don't have those, you can't come to believe in aliens. No space, no space aliens. Firmament? No space aliens. Flat Earth? No other "planets" billions of miles away.
There's that video of the lady who had been friends with Werner von Braun who related that von Braun kept telling her that the "last card" they would play would be an alien deception.
I think Muslims would instinctively reject any notion of an alien pretending to be a messenger of Islam. NO Catholics - I'm honestly not sure of, but I think Trad Catholics, along with Orthodox and conservative Protestants would instinctively reject such a notion too. Just based on the personalities of people I've interacted with from these groups, and their opinions on aliens/UFOs/space/etc., I could never imagine them accepting such a prophet en masse.
I think any idea of the Antichrist earning the following of the entirety of humanity would have to rely on most of humanity becoming atheist first. Or else that he only convinces certain sectors of humanity, since, as the rest are all non-Catholic anyway, they are already damned.