Pamela Aprodia:
To get the fifth Resonance Amulet, you must destroy the Archon of Halisha. Find the devil in the Imperial Tomb or at the Wall of Argos.
If you go to the Imperial Tomb, you can confront him by entering the Four Sepulchers. If you go to the Shrine of Loyalty, you must attack his minions as you see them. Then Archon of Halisha will appear. Keep in mind that you must destroy him to get the Resonance Amulet. OK, leave now! MMMMMAH!!! This is the kiss of luck!.