Moonlil
A former grigori that was turned into a "Sister" by Sevothtarte to take care of Sara after awakening in Jibril's body. She is a "Staker", a sister who has been lobotomized so that she will not disobey the orders of her masters. Thus, she has a very childlike personality and is very fearful of Sevothtarte. Initially she was only called "Sister" until she brings Sara a bouquet of Moonlilies, she remarks that they are her favorite. So Sara names her Moonlil after the flower and Moonlil has since nicknamed herself "Lil-chan" as a result. When Sara (as Jibril) escapes before her trial, Sevothtarte holds Moonlil captive in order to lure Sara back. It is also speculated that Moonlil, later called Ruri by Sara, may be Ruri. Though it is only a speculation, the similarity in name and friendship with Sara as well as personality back up this theory.