Yunyun

This eccentric and energetic young girl is one of the Borners, surviving test subjects of Snake's Ua virus experiment. The Ua mutation did not appear to have granted her any extraordinary ability, however, causing her to be treated as a disposable pawn by Liang Qi. A comic-relief who was also made fun of for her almost-flat chest, she was variously tasked with things from spying, (unsuccessfully) infecting Japanese representatives of Shanghai Anti-Terrorism Summit with Ua virus, and (again unsuccessfully) killing Canaan.
(Source: Wikipedia)