Abaddon Shrine

Abaddon Shrines are located in the Great Margonite Temple during the quest A Show of Force. They have to be destroyed using a Rune of DOOM.

There are 6 shrines down both the North and South walls of the Great Margonite Temple (totalling 12), activating the shrine with the Rune of DOOM in your inventory and the quest A Show of Force will spawn a group of 5 Graven Monoliths and certain numbers of Margonites (see here for reseach), the most South-Westerly Shrine spawns 5 Graven Monoliths and 3 Margonite bosses: Dupek the Mighty, Hauseh the Defiler and Tanmahk the Arcane.

Locations
The Desolation
 * The Sulfurous Wastes
 * Great Margonite Temple (only during A Show of Force)