Giratina Lillie is a version of Lillie that has been corrupt and possessed by the Lord of the Lost, also known as Giratina.  This has turned Lillie into a psychotic and malicious force of nature that almost never shows even an ounce of mercy.  Giratina's wings can be seen coming out of Lillie's back along with her clothes taking the colors of parts of Giratina's body, more specifically the red and black.  In addition, Lillie's eyes have become black with red irises to resemble Giratina's eyes.