Tasha Robinson of Sci Fi Channel's "Sci Fi Weekly" commented that it was difficult to decide whom to "root for" as the witches seemed to be insane killers, but the protagonists were "killers of a colder, more controlled stripe" and were generally unpleasant, with the exceptions of Karasuma and Zaizen. She also noted that the characters give no indication as to why they work for the STN. Robin and Amon's character designs are said to be strange. The series' setting was said to be "a fairly severe, almost oppressive gothic design" and that the color palette and the plot's focus on the occult contributed to the dark feel. The pace steeply picks up once the protagonists head into battle. It is also noted that the series' could have afforded to reveal more information earlier in the series instead of teasing the audience with mysteries; just like many other reviewers, she comments that the mysteries were worth the wait.