Diram's Castoffs

During the Draconic Wars, Keothi Diram summoned and bound thousands of demons and elementals to the Material as troops against the Tritons and Yuan-Ti. Some of them have survived across the centuries, wasting away over time and unable to return home.

At least a faction of them is after Riga. A group, led by Azzrukhan, tried to ambush her at Graal Lark's place after killing the journalist.

They are led by an individual known as Zarzathel.

Azzrukhan was in possession of Gloam Essence crafter by some unnamed shaman clad in wolf furs.

It's fair to assume that mortals are collaborating, willing or otherwise, with this lot.