We are told in Scripture that a Great Apostacy will happen in the future in both Matthew 24 and 2 Thess 2:1-7 . What will this Great Apostacy look like? We're given a detailed picture of that in Matt 24, but many Protestant prophets have another prophecy they often "prove" from Scripture, that being that Catholocism will be the state religion, that the false prophet will be the last pope. Thus , protestantism will fall and all those nominal believers will become Catholic.
In my expectations, I think it will be much the other way around. I expect some re-branding of New Ageism will lead the state religion of the False Messiah. Most REAL believers within the Catholic Church will stay faithful, while the nominal ones will apostate from the Catholic Church and join the New Age movement. We all know that any religion that rejects Yeshua as the Messiah is a straight ticket to eternal torment, but I suspect people will either apostate from Buddhism, Hinduism, Islam, etc., or blend it will the New Ageism being promoted by the false prophet as well.
I expect that Bennie C and his Maitreya will be a lot closer to what the false prophet and false messiah will look. If these two AREN'T the false prophet/messiah, I am expecting someone a LOT LIKE them.
It would not surprise me if every denomination apostated as a denomination. It would not surprise me if the Catholic Church apostated from the Gospel and embraced the error of the false doctrines of the false messiah. It would not surprise me if the Baptist Church did the same, or the Methodist Church, or many others. In fact, G-d likes to test us and this would be a great way of testing whether we have put our faith in a man-made organization or in Him personally.
But if that happens, Malachy was wrong, because he said the Catholic Church would endure to the end and remain faithful to G-d until Judgement Day, and that Petrus Romanus - the last pope - would steer the Church through that faithfulness. The only way the last pope could be an evil guy is if Malachy was wrong.