Shirakess Grimoire

Shirakess Grimoires drop from the following Shirakess naga in Nazjatar:
 * Broken Blackfin
 * Shirakess Apprentice
 * Shirakess Enthraller
 * Shirakess Overseer
 * Shirakess Subjugator
 * Shirakess Voidreaver
 * Shirakess Voidtwister

As a quest objective

 * Overdue