Xia Xia

Xia Xia is an E-rank regular that lives in the 28th floor. This regular's gender is as of yet unknown. Xia Xia is most likely inactive, and makes a living as an informant, selling information to others. She is most likely a light bearer (we can see her using a lighthouse in Chap127), but we can't rule out possibility of being an information collecting scout like Apple as well. Horyang goes to him/her to find Cassano in the Devil of the Right Arm arc. She also sends Koon's team after Casano, too.

Assassin from Chapter 127 described Xia Xia as a woman with bunny ears. Story continues with Xia Xia helping Baam to get to the location, where he can find Teddy (Kang Horyang). Xia's motives are unknown, because she hired that assassin and she is definitely hiding something.