I suggest that the quest line "The Taken War: Petra" gets updated with a few more steps that culminate in a Battle at the Court of Oryx.
However, the Queen doesn't want you to kill the target, she wants this one captured to use in the Prison of Elders.
Prison of Elders
New level 42+ Taken Battle
All rewards 300-310
All previous Prison of Elders content level scaled accordingly.
Taken matches added to all previous Prison of Elders content.