Draco in Leather Pants: The manga includes fan art people have sent in which disturbingly portrays characters like Saki and Riruka in saccharine settings, despite their horrific actions. There are also a lot of fans out their who cosplay as Saki.
Nightmare Fuel: One of the sickest examples comes from the second volume when one of Riruka's minions, a pervert called Norota, summons his personal zombie. Norota is a slimy creep who makes it blatantly clear that he would've had his way with young Mayoh, and controls his zombie, an imbecilic executioner named Kenneth, with a little girl doll. Norota does so by offering to show Kenneth the doll's panties if he kills for him. The other summoners, and Reiko, are extremely disturbed by Norota's actions.