Tweet of the Day: Episode 26- Get Urras back to Anarres
The Fundamentalist, the perfect card carrying villain, unyielding in its beliefs and willing to do anything to fulfill them. They make for implacable enemies that simply will not give up. A good way to justify hordes of goons throwing themselves at the hero(s) headless of losses. The fact that they are also dogmatic in their world view makes arguing or even understanding them so difficult that putting a bullet (or a few dozen) in them is seen as a mercy.
This type of villain is rarely the Big Bad, since their adherence to their beliefs tends to alienate the audience. However they do make for a good second in command who obeys the chief villain without question. Often the Big Bad is not a true believer but someone who has discovered a way to manipulate the fundamentalist beliefs for his own means. Makes it all the sweeter when the big bag is unveiled as a unbeliever. Karma often comes in the way of the mob crushing him under his weight.
Of course, a fundamentalist can be tragic in his own way, specially if the point of divergence from the heroes is not in believes but in methods. But this tends to track with other tropes such as the Knight Templar. Unlike the Templar, the fundamentalist is a tribalist. Their sense of right and wrong often serves to define membership in his tribe and only applies to members within it. Outsiders can and should be treated with contempt if not destroyed as a threat to the tribe (be that tribe organized along religious, wealth or political lines). In other words, the same actions that would be condemned if committed against the members of the fundamentalist group are perfectly acceptable against members outside of it.