She dug the Underworld with a spoon (in lazy defiance, because she was supposed to be destroying worlds and capturing souls for her mother), and while in there learned the horrible truth about her parents. Upon trying to warn her sister, Bala, she was forced into a blood-contract under the conditions that should she speak an untruth to Bala, she would be ripped apart atom by atom.
She spoke the truth to Bala, about their parents being two ancient deities, the Painweaver and the Trickster, and that they planned to consume all of existence across the multiverse and force all living things into an eternity of ceaseless agony and suffering.
Bala and Ataxia are now dead-set on destroying their parents.
Demons and their family squabbles. Whaddya gonna do?
[This is a character for The Heroes of Tittia (THOT), a roguelike RPG-universe commission type of mine in which you can create an adventurer and go on a silly sexy horny adventure and have your character get armor, weapons, blessings, curses, etc. similar to Corruption of Champions]