How does the author use foreshadowing in The Neverending Story?

In Chapter Twenty, Bastian elevates Xayide to a position of prominence in his company and succumbs to her flattering attentions. Xayide's ability to manipulate Bastian with her lies embodies the scenario that the werewolf Gmork alluded to earlier in the novel. Through this early foreshadowing, the reader can now see that Bastian will soon become the enemy, not the savior, of Fantastica.