Tentang
Had a short cameo in episode 2.
Takeshi Kurisu seemed to be Ayumu's teacher, but in fact he is the strongest Masō-Shoujo, Chris. She used to be Ariel's top pupil but was turned into a plain middle-aged man by the Queen's curse. That was her punishment for being the leader of a coup that Ariel concocted a century before the events of the series. Since then, she has been plotting her revenge against Ariel for letting her take the fall along with some of the others involved in the coup. Due to her strength and her status as a villain, she can be considered the Masō-Shoujo that all Masō-Shōjos fear. She can turn back to a Masō-Shoujo while she is drunk thanks to her friend Naegleria's ability to cancel magic. She makes a cameo in episode 12 of the anime adaptation in her original form, indicating that she was under the influence at the time.
(Source: Wikipedia)