Dispatching the Destroyers  

1. Head back to Najena's Cove and kill any of the mobs that start with "an invading". You need 6.
2. Return to Pallasa Rargon to complete the quest.

NOTE: This quest is repeatable for faction and now allows you to obtain quests from Marathan Allim. Given the broad definition of targets for this quest, be sure that you have this quest at all times. Everything else you do will count towards it, and even after you have max faction, this is an east, repeatable, 20 . you should be able to do this quest twice for each repeat of one of the Cleansing quests.