The Watcher of the Mists
Mastermind of evil things
Both Xanesha and Lucretia referred to their “Master,” for whom they conducted rituals which included the Sihedron Ritual. The victims were apparently chosen due to their greed in life. Before their fight with Lucretia, she offered them a chance to join her. “Mokmourian would be very pleased to count you as allies! You would be well-rewarded.”
Who or what this Mokmourian is, and why greedy victims are being sacrificed to him has not yet been revealed.
Update: When the Sandpoint Heroes interrogated the defeated stone giant Barl Breakbones on 12 Kuthona 4707, Breakbones identified himself as “Servant of Mokmourian,” and that Mokmourian was the “King of the Giants.”