[Tallahart] An Unlikely Source
Start it with Phantom Seal in Phantasmal Night Sanctum. Complete it with Aoe in Grave of the Gods.
Requirements
Lv. 290+
Quests
NPCs
Locations
Phantom Seal Start
Aoe Complete
Connected quests
Dialogue
Turning in the quest
Additional replies
You already investigated the sanctum. Report back to Aoe.