Vaetir

A Celestial goddess residing in the depths of the Abyss, she’s easily identified by the massive carcass of a former Demon Lord that she’s taken residence in, wearing and using like a puppet. Bearing this striking and monstrous face, she systematically subjugates and takes control of creatures in the Abyss that show vulnerability, from lost souls with no master to victims who have gone mad from spending too much time in the horrible lower plane.

She exerts her influence over these chaotic creatures that would normally listen to no one with terrifyingly effective manipulative tactics. She finds what they want most in life and ruins it for them, breaking the individual down until there’s no point in them getting what they want. She then builds them back up on her own terms, making them dependent on her and willing to do whatever she says, not out of loyalty, but because their desires have been ‘rewired’ in a way that’s convenient. These tactics were partly responsible for the war in the Lower Planes losing steam, as she continued to undercut the point of victory with psychological tactics.

She’s a woman who thrives on tragedy, seeing the dark, toxic side of a person’s psyche as the best part of them. Members of her cult tend to be nihilists who are willing to destroy themselves in order to have what they never can or struggle with their own existence. She coaxes suicide victims and those who are steeped in despair before their death to join her side. Her worshippers typically refer to her as ‘mother’ or some other term of endearment and are dogged blasphemers of the heavens, feeling abandoned, spiteful, and hateful toward gods and their efforts.

Other Demon Lords and Archdevils who were around when she first arrived in the Abyss know her identity from before she dominated and took the place of a Demon Lord. Verilean, the Mother Earth, was one of the original beings who emerged from the Void and came to the Material Plane to give birth to the mortals who would worship gods. She herself molded the bodies of Humans, Dwarves, Gnomes, Halflings, Firbolgs, and Goliaths, along with a few other mortal races as well as the first Solars. However, she was against the war with the Primordials and other gods and did everything in her power to put a stop to it, to no avail. She felt the pain of the mortal creatures who were caught up in it all and began to hate the other gods for their selfishness. This broke her mind and she descended into the Lower Planes where the monsters residing there were at least honest about their cruelty.

So she’s a being who loves humanoids but despises gods, wishing to see them ruined. She indulges in the perverse irony of how the world works and prefers to embrace all facets of people, especially the evil parts. The last time she was scene, she was a towering adult woman shaped by her round stomach, loose skin, and Buddha like physique. Her skin flaked like dry clay and her hair was made from forests and rivers. Verilean was the goddess of the Earth and fertility before her descent and once spent centuries giving constant birth to lesser celestials, but hasn’t done so since the Great Event. It’s unknown what she looks like currently beneath the carcass she pilots, but she wouldn’t fit at her original size. She’s still frightfully intelligent, reasonable, and is far less chaotic than the other demon lords, almost comparable to a devil, but she often does chaotic things just to prove a point. She likes to wax philosophy, questioning why and how the world works, and prompting an opinion from others just to see how they answer. She makes alliances and ceasefires with her enemies as often as she starts hostilities on a whim.

Blessing
Those under Vaetir's love also inherit her madness, to some degree. Just as anyone who enters the demonic goddess' lair or stands in her presence succumbs to a madness that strips them of hope and replaces it with self-destructive pursuit for unattainable self-fulfillment, those who worship her get proficiency in wisdom saving throws and an immunity to fear. This boon fades as soon the subject drifts away from their faith in Vaetir.