The Oracle of Delphi prophesied that when she herself next bathed in the waters of Delphi she would die. In order to avoid this fate, she span a new prophecy stating that Eve Baird would be killed by the Reaper inside the Library when an hourglass ran out. Since Eve was not in the Library when the sand in the hourglass finally pooled in the base, the Reaper claimed the Oracle, and declared "Eve Baird - released".
The Oracle masqueraded as "Nina Mitrani", a timid Hispanic high school cleaner, in order to delay the Librarians and stop Eve contacting Jenkins, and while pretending to be Nina she spoke with a Hispanic accent and occasional Spanish words. When her mask was stripped away, the Oracle had a British upper-class accent, and a boundless ego.
The Oracle stated that Eve had a prodigious destiny as a Guardian, a role to alter history, and that this was why she had been targeted.