I'm going to assume that's the one you are referencing. And I will say, never say never, mas. No pope can order a Catholic to commit murder? How about Pope Urban II in 1095. Or during the next 200 years the eight futile crusades that popes sent thousands of crusaders to die for? And Gregory IX instituting the Roman Inquisition in 1231 in order to purge the Church of heretics? And then there is the Spanish Inquisition (1478-1820). Do not say that Popes cannot order a Catholic to commit sin. Unless you believe that killing non-Catholics isn't a sin.
Just war is not sinful. The Eastern Crusades stopped the Muslim advance from that direction for several centuries. The Iberian Crusades eventually rolled back the Muslims.
The Inquisition was confined to investigating public, baptized Catholics plotting to overthrow church and state. Public Jews and Muslims were outside the scope of the Inquisition and it did not operate in places like France or Germany were there were Protestants. Only those Catholics who did not repent were burned at the stake. This treatment was far more humane than the ripping out of the intestines of those English, Scottish, and Irish Catholics who refused to apostatize.
The Iberian Crusades could not have succeeded without the Inquisition. Aside from abuses that inevitably occur in war, how was any of this sinful?