Similar to summoning Phar'Ahkt during the quest, I Seek Knowledge, in order to summon Orus'Dakh his name must be spelled out using runes. Alternate methods of spawning Orus'Dakh are to hail him after another player hails him, or to share this step of the quest in a group. The runes formerly used to summon Orus'Dakh are not consumed when used. They were:
orus (note: This rune is particular seems to have a VERY low drop rate.)
Pick up the following artifacts within the Residence Court. These items spawn and despawn randomly every few minutes:
a bucket of spoiled meat at ( -278, -5, 350 ) Copy/waypoint -278, -5, 350 or ( -280, -5, 408 ) Copy/waypoint -280, -5, 408
a bottle of spoiled wine at ( -301, 17, 417 ) Copy/waypoint -300.63, 17.18, 416.54 or ( -380, 4, 425 ) Copy/waypoint -380, 4, 425 (on a narrow ledge 2/3rds of the way up the building, you will need to complete the Oily Wall quest to reach this)
a pot of spoiled coffee at ( -547, -8, 458 ) Copy/waypoint -547, -8, 458 or ( -486, 22, 374 ) Copy/waypoint -486, 22, 374 (on the narrow protrusion out from the roof, easy to miss)
a pot of spoiled soup at ( -355, -9, 370 ) Copy/waypoint -354.56, -8.89, 369.70 or ( -322, 8, 350 ) Copy/waypoint -322, 8, 350
a crock of spoiled cheese at ( -354, 12, 500 ) Copy/waypoint -354, 12, 500 (on the ledge near the oiled wall) or ( -300, -7, 507 ) Copy/waypoint -300, -7, 507 (behind the pillar)