Given the task definition and input, reply with output. In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.

Passage: Bastian Bux is having troubles at home: his father Barney's busy workload is keeping him from consoling Bastian's fear of heights, which in turn is hurting his chances of joining the school swim team. As such, he then heads to an old bookstore where he again meets Mr. Coreander, who proceeds to help find a book on courage. While waiting, Bastian rediscovers the Neverending Story's book, and is shocked to see its words disappear off its pages. Deciding to take the book instead, Bastian returns home and finds himself able to claim AURYN right off the book's front cover while hearing the Childlike Empress summon him to Fantasia.
Aware of Bastian's arrival and purpose, an evil sorceress named Xayide orders a creation from one of her servants to stop him. The servant creates a memory machine that will strip Bastian of a memory each time he uses AURYN until he is unable to remember where he came from, or why he is in Fantasia. Xayide then sends a bird-like creature named Nimbly to persuade Bastian into making him wish. As the two arrive in a populated area of Fantasia called Silver City, the sorceress sends large monsters referred to as giants to attack. Despite Nimbly's attempts to make him wish them away, Bastian is able to escape from them without doing so. After falling into a secret passage, Bastian is contacted by the Childlike Empress, who tells him of a new threatening force to Fantasia, which is keeping her prisoner in her own castle as well as causing the stories of the ordinary world to disappear, and that he must identify and defeat it.
What is the name of the sorceress who sends monsters to attack Bastian?