Complete Monster: Wolfram, the keeper of the titular fortress, is a handsome, gentle looking man who, despite his Faux Affably Evil manner, is a genuine sadist who has no qualms about hurting women or children. Everyone passing through Sankt (Saint) Gotthard Pass must be inspected by Wolfram, the bailiff of the Wolfsmund ("Wolf’s Maw"), who delights in mentally and physically tormenting his victims. Starting the series by having a young woman executed and her body displayed, Wolfram is responsible for many atrocities, including: torturing a boy (a teenager at most) by burning the soles of his feet, and then forcing him to stand, holding his father on his shoulders to prevent the man from being hanged; forcing a little girl and her mother to undergo a search inside their "hiding place" with tongs to see if they're hiding anything (then keeping the mother as a prisoner); participating in torture ostensibly for information but really for pleasure; and feeding the mother and younger brother of one of the only people to escape his clutches to ravenous wolves for an execution. It is revealed Wolfram led violent raids to kill civilians in the past and spared only two siblings, but only after putting out one eye each; even after they reveal themselves to Wolfram years later, he claims not to remember them. Ostensibly loyal to the Austrian Hapsburg Dukedom, Wolfram admits that his only reason is for the amusement it gives him and his greatest joy in life is to cause others pain, especially after giving them hope first. Finally, when the fortress is attacked, he flees, leaving his men to fight and die against overwhelming odds (and killing one who suggests surrendering).
Darkness-Induced Audience Apathy: Given the monstrous nature of the protagonist and the sheer amount of bullshit that any heroic character has to suffer through, a number of readers have trouble getting through the story.