Against the coming storm
Known as Agera of the Shadow Face (both because of her powers over shadow, and her propensity to manifest as wearing a veil or mask of some kind), Agera generally appears in the form of a tiefling / demoness / succubus and exhibits powers of seduction and mental control.
the party first encountered Agera in Darguun when a tribe of goblins was attempting a mass sacrifice in order to summon / resurrect her. The party stopped the sacifice, but not before a small portion of her was allowed to press through into the world. She negotiated with the party, offering knowledge and assistance with the trails ahead if only they allowed her to escape her extradimensional prison. When the party refused (not quite in unison, mind) and attacked her, she summoned infernal armor creatures similar to warforged to defend her. The party prevailed and her incursion into the world was disrupted.
The party next encountered her works in Thelanis (the Feywild), near the border of the Pyrmaid, where an expedition of gnomes was attempting to uncover evidence of a civilization where they had been dominant over the Eladrin (whom they now considered to be oppressors). Visions of the past revealed that they had worshiped a gnomish-looking version of her, used similar ‘warforged’ assistants and eventually developed into a tiefling-like race, before being overthrown. They came to an abandoned and mostly destroyed temple, where she again offered her assistance in return for freedom. Roswynn used a portal to travel with her to learn her secrets, while the rest of the party destroyed what they could of the temple and its approaches.
She was again encountered in the Pyramid, where she existed in purely physical form (possibly her home plane?). There, she had taken the guise of a priestess of the Silver Flame. (Though there seemed to be some liturgical and iconographic focus on the shadow in the flame). She said she knew it was their destiny to die in the temple, but if they promised to help her escape it, she would ensure their resurrection in the mortal world after. The party refused her ‘generous’ offer, leaving her to continue her ‘ministry’.
In Dol’urrh, on the road between Gloomwrought and Winterhaven the party has run into evidence of her works again. Here, they found a church dedicated to Dol’Arrah goddess of light and aspect of the Sovereign Host… but it seemed all the status of Dol’Arrah look strikingly similar to Agera, and Magistrate Padraig was there accusing them of having been subverted by a succubus. The party moves in to investigate, once more…