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.
The household's nonchalance regarding the obviously troubled child in their midst
The Antichrist doing chores around the house, up to and including collecting his mother's used panties
Complete Monster: Fabius, who made a deal with Satan to make Lucius the Antichrist, and above that, doesn't give half a shit about his family, even after his son's death. Fortunately you can give him his just deserts.
Lucius himself arguably counts. He barely seems to care when Lucifer appears before him and tells him to begin reaping souls for him. He also finishes the game by killing everyone close to him and making cutesy comments about it in his journal, though he does seem a BIT sad about killing his mother.
Evil Is Cool: It is. It just is. Telekinesis, Mind Control and oh so many more deliciously evil powers. What more can you want?!
Uncanny Valley: This is one of the few cases where limited animation works. Lucius seldom has anything but a blank expression on his face and it's creepy.