Enter The Den of the Devourer ( 82, 93, 895 ) Copy/waypoint 82.24, 93.46, 894.73 and destroy ten tomes:
These are approximate locations, so if the tome is not at the specific point, look around. Also, some of these will be visible, and other will be invisible - chosen at random. If a tome is not appearing at a location, use a visibility spell/ability or an AOE ability.
Important: Do not kill the Devourer before you have destoryed all of these tomes since you will need to kill it for the next step!
The Carnovingian, or its placeholder, a carnoligian, on Carrion Briar around ( -140, -70, -520 ) Copy/waypoint -140, -70, -520.
The Carrion Mandragora, or its placeholder, a carrion mandrake, on Carrion Briar, down the underwater tunnel at ( -240, -80, -450 ) Copy/waypoint -240, -80, -450. Note that the placeholder typically spawns nearby at ( -200, -146, -390 ) Copy/waypoint -200, -146, -390.
Examine The Crystal of Drukaunis that you received earlier from killing The Devourer.