If we imagine that puppet-master aliens are taking over a portion of the country, and that their dominance will spread if their human hosts aren't killed and burned, I think we have a situation analogous to what Torquemada thought he was dealing with.
So, while I'd consider the real Torquemada extremely evil -- specifically, Lawful Evil, in D&D terms -- I could easily consider his demon-hunting fantasy analog as Lawful Good. He's exterminating evil cultists, evil cultists who have swayed the king (and other nobles) to their side, tempting them with gold -- all as a first step toward toppling a righteous kingdom of His followers.
So, while I'd consider the real Torquemada extremely evil -- specifically, Lawful Evil, in D&D terms -- I could easily consider his demon-hunting fantasy analog as Lawful Good. He's exterminating evil cultists, evil cultists who have swayed the king (and other nobles) to their side, tempting them with gold -- all as a first step toward toppling a righteous kingdom of His followers.