"The bare fact that the whole second half of Exorcist II concerns a Catholic priest acting upon revelations from a pre-Christian Mesopotamian demon should be enough to tell you that this movie takes place in an entirely different moral and metaphysical universe from The Exorcist. Simply put, this is what you get when you hand over the reins of a sequel to somebody who openly detested the original film. To all appearances, Boorman deliberately did the opposite of everything that had worked in The Exorcist, or that would have made sense as a continuation of its story. Father Merrin, the Van Helsing of the previous movie, was originally the perfect embodiment of the Roman Catholic Church as believers would like to conceive it, a wise yet humble representative of a stern yet benevolent authoritarianism. Boorman, having none of that, recasts him as an institutionally embarrassing rebel, a man who discovered and proclaimed a secret truth despite all the obscurantist obstruction that his bosses could throw his way. Regan MacNeil was originally a collateral casualty of the struggle between Good and Evil, a bystander whose innocence was itself the point. Pazuzu picked her precisely because there was nothing special or important about her; his true target was always the faith of Regan’s would-be rescuers, and the injustice of his attack on her was itself his strongest weapon against that faith. Again, Boorman has other ideas, and we are now asked to believe that Regan is Jean Grey for Jesus, with Merrin (or Lamont) and Pazuzu squabbling over her allegiance like Professor X and Magneto. Most galling to any thoughtful fan of The Exorcist, however, is what Boorman has done with Damien Karas. Karas, after all, was the real hero of The Exorcist, and his eventual victory over Pazuzu was the most stridently and specifically Christian thing about it. It was not strength that defeated Evil in the end, but literally Christ-like sacrifice, as Karas surrendered his own life — and, if you're a pre-Vatican II Catholic, his own soul — to lure the demon out of Regan. There was no way to tell the story that Boorman wanted to while acknowledging that turn of events, so I guess we shouldn’t be too surprised that Exorcist II ignores Karas completely, refusing even to mention his name. Absolutely the only recognition Karas receives in the sequel comes by implication, as one of the oft-mentioned three deaths that occurred at the MacNeil house four years ago. To be fair, there probably is a compelling and thought-provoking movie to be made on the premise of Exorcist II — it just wouldn’t be a sequel to The Exorcist, and Boorman’s determination to make it one reveals his contempt not only for the earlier film, but for that movie’s fans as well."
—Scott "El Santo" Ashlin, 1000 Misspent Hours And Counting
