It was Satan who described ML as uptight. Yes, I wrote it, but I intended it as Satan's opinion, not my own. I would imagine most Protestants see the result of the PR as a good thing for Christianity, otherwise why not become Catholic? At the time of the split, though, Catholics, especially the clergy, would have seen it as a disaster, and would surely have blamed Satan.
To view the PR as a good thing, the obvious conclusion is that 45,000 different denominations is also a good thing, hence my logic for the book that Satan can't conquer a denomination with no central figure to overthrow. Though Jesus prayed for unity, he also would have known what would eventually happen, and he didn't say Christians should remain forever unified under Peter and his successors.
His prayers are, of course, more than just a biography of important events in his life. Since he knew what would happen, his documented prayers are also his ongoing encouragement to readers of the Bible to remain unified. If Christians remain unified in their beliefs but not in who governs the Christian Church on Earth, does that mean Christ's prayers went unanswered?
I think the Christian faith is unified in the ways that matter most. You worship the same God, believe in the Trinity, the Resurrection, and the Virgin Birth, among other core beliefs, and you follow the teachings of the same Bible, more or less. And your faith can't be overthrown or corrupted as easily as a single Church hierarchy can.
Put all that together and the PR was a disaster one could blame on Satan. The fact that Christianity as a whole remains unified over core elements of the faith, suggests to me the outcome is actually a good thing. It seems like a great example of God using evil to do good.
Ultimately, it will be Satan who claims to be the cause of the PR, but the Catholic cardinal he converses with can point out that he's the Father of Lies and not necessarily to be believed, and the cardinal can make the counterarguments that I do above. Words to the effect: Satan, you may have caused the split, but God used it against you to create something even more indestructible.
The alternative would be to say that Satan wanted what has happened, including the 45000 different Protestant denominations, but that they will all come back together eventually. In fact, that's what Satan and Connor intend to do: conquer the biggest denomination, and then convert the rest back to Catholicism.