In episode 6 of Chuunibyou demo Koi ga Shitai!, Rikka gives the members a "uniform" which is a black shirt with 2 kanji on the front. Hers reads "Evil Eye" (jagan), Yuuta's reads "Dark Flame" (yami honoo), Kumin's reads "Black Dream" (kuro yume), and Dekomori's reads "Purgatory" (rengoku).
I think they never mention what Kumin's or Dekomori's say, so I had to translate them myself, and Kumin's made sense, but I don't understand Dekomori's. Is there any other reference to her as "purgatory" or anything?