These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Mautz is a close second, for not only allowing Virgil to threaten his daughter in front of him, but let him hunt her down like an animal, and attempts to force Eric into his manhunt. Any pity for him is lost when he blames Eric and Steve for Mark's suicide attempt. After his "church and state are one and the same" speech, he may as well be Virgil #2.
Moral Event Horizon: Crossed repeatedly by Virgil Byrnes (he doesn't have an entry under Complete Monster for nothing); crossed a few times by Mautz, such as when he attributes Mark's suicide attempt to the other students in Lemry's class.
Nightmare Fuel: Sarah Byrnes' facial scars. Though how she got them is good for a few sleepless nights, too.
Virgil stabbing Eric, and then chasing him through town with the knife still in his skin. And Dale having to remove the knife with his bare hands. If you have a weak stomach, do not read that spoiler.
The Woobie: Eric, Lemry, Ellerby, Jody, Sandy, Carver... This one, 216-page book rivals the entire Harry Potter series as a deep, dark pit of Woobiedom. (And for the record, Harry Potter has a Woobie page to itself.)