Now things begin to get interesting. The High Middle Ages. The Crusades, and the rising secular power of the church culminates with Pope Boniface VIII. In his effort to secure complete authority for the Church Boniface had some rather pointed conflicts with various Princes, which eventually lead to his death after a period of captivity - and the establishment of the Avignon Papacy. For the latter, alone, one might be willing to nominate the man for Demonhood. I think, however that Dante was on the money when he damned the still-living Pope in his Inferno for the destruction of Palestrina, and killing some six thousand souls.
If you’re interested in that sort of thing, reading the Wikipedia article is particularly interesting for the posthumous attempt by the King of France to have the former Pope excommunicated. Some of the quotes from the council (Which, apparantly couldn’t make up its mind.) are particularly modern-seeming. Others are nihilistic to a degree that would frighten me from anyone, let alone a medieval prince. Many are both at the same time. 
Pope Clement V was the pope who actually began the period of the Avignon Papacy. For all the flaws of this period, it is not something that I will say is demonic in it’s nature. Like Adrian IV, I don’t like the effects of the decision, but Clement V seems to have been trying to remove the Papacy from the control of several families in and about Rome - a goal I can’t exactly condemn.
This doesn’t mean that Clement gets a bye from me. He’s also the Pope who supported Phillip’s destruction of the Knights Templar. While there is some question about the holiness of the Knights, it is generally believed that the charges against the order were drummed up simply to allow Phillip to raid their coffers. Weakening the Church as a military power can’t be ignored, either, even if the Templars had not exactly been the most obedient of orders. There are other scandals associated with Clement, and he established the Jubilee, too - which helped to pave the way for the Protestant Reformation. So, yeah, Demonic. VERY Demonic.
Another aside, here. I’m not trying to claim that the Reformation was a bad thing. By the time it happened the Church was quite venal, as I think my willingness to make this list will show. However necessary it might be, however, doesn’t change that the Reformation also lead to some of the most bloody, destructive and immoral periods of history. Steps that could have avoided the need for the Reformation but not taken are thus going to be very high on my list of probably Demonic actions.
I’m going to put Pope Sixtus IV on the list of Demonic Popes. Yes, he did some things that were/are admirable - most notably comissioning the Sistine Chapel. But he’s also the Pope to acquiese to the Spanish Inquisition, even if he tried to repudiate the greater atrocities of that office. His personal life was…questionable, at best. He instigated wars for the goal of providing his relatives with thrones of their own, and then abandoned allies. He sold indulgences. He’s even rumored to have fathered his sister’s son.
Immediately following Sixtus was Pope Innocent VIII. To say the name is ironic understates the case. At the time of his death he left behind sixteen children, all of whom he had bestowed nepotistic offices upon. He is also responsible for giving Henry VII of England right to the kingdom by the threefold right of Blood, Conquest, and Popular Choice. As I suspect Henry of the murders of the little princes I find that more than a little ironic. (BTW - Henry VII definately makes the list of Demonic Kings.) What particuarly incites my anger against this Pontiff is that he supported the witch-hunting craze by issuing the proclaimation Summis Desiderantes, which was pivotal in making Malleus Malefacarum the text on witch-hunting for the next several centuries. Although later condemned by the Papal Inquisition, itself, the Malleus Malefacarum remained the textbook for how to find, test, and destroy witches.
Now, the one Pope I knew, before I began this research, that would be on my list: The former Rodrigo Borgia - Pope Alexander VI. To begin with there is the suspicion he bought the election that made him Pope. While he was an able adminstrator, and actually rather restful theologically, after the actions of Innocent VIII, his passion of nepotism was such that he was willing to plunge of all of Italy into war for the purpose of enriching his children and relatives. He made his sons Cardinals, and while there is reason to believe that Lucreita is innocent of the crimes normally ascribed to her, she was used by Alexander ruthlessly as a prize for his secular goals. I think the most condemnatory thing one can say about Alexander was that he was a true Rennaisance Prince - with all the greed, venality, and evil that entailed. I don’t even need the pretense of Angel to think this was a truly Demonic Papacy.
His successor, Pope Pius III, tried to begin reforms from the court that Alexander established, but died after only twenty-six days.
While Pope Julius II was a strong leader for the Church, he was also so focused on martial glory he provoked several wars in Italy, and acted far more as a secular Prince than my estimation of Pope. Considering that the Wikipedia article listed here also includes a summation of Barbara Tuchman’s condemnation of this man, I’m willing to go with my instict that says so war-like a Pope is likely Demonic.
Just look, we’re only up to 1513, and I’ve already lost track of how many Demonic Popes we’ve had. And if we skip Pius III there’s four - in a row!
At this point, I’ve gotten a little bored with this. And, well, breakfast is almost ready, so I’m taking a break. If there is interest in more Demonic Popes, I’ll continue this later. It certainly is an interesting study. (If a little disheartening.) It’s nothing that I find surprising. I just wish it weren’t.
I hope you’ve enjoyed this fruit of insomnia. 
