Thraxxia

Daughter of the demon lord Graz'zt and her father's personal assassin, Thraxxia played a part in Nexus' history when she made a warlock out of a man named Myster E. Deciding she needed a new weapon, Thraxxia opened a hole to the Abyss under the hapless mortal and offered to "help" him get home in exchange for his servitude. A simple villager with no knowledge of magic or demons, the man agreed. The two formed a pack that gave Myster E access to the magic of a warlock, though the powers manifested as those of a hexblade rather than one who'd made a demonic pact.
Myster E eventually figured out that Thraxxia wanted a new weapon and believed she was using him to create a magic sword she could later claim for herself. His theory was somewhat correct; she was making a weapon but it was not to be the sword Myster E wielded. Rather, Myster E himself was slowly being transformed into a hexblade by the magic Thraxxia had given him.
Myster E contacted Thraxxia several times throughout his adventures, often seeking advice. She proved to be very whimsical during these conversations, often teasing her warlock with just enough information to lead him down the path she'd laid before him. On one of these occasions, Myster E reached her while she was in the middle of slowly, brutally executing several of her father's enemies and answered his questions in a cheerful manner while screams of agony echoed in the background. In another instance, Thraxxia appeared annoyed with Myster E for interrupting a conversation with her mother by contacting him.
Thraxxia first appeared to the rest of the Barrel Boys in person shortly after they managed to slay a blue dragon. Seeing the daughter of her hated enemy Graz'zt through the eyes of her cleric Marshall, the goddess Waukeen became enraged and ordered Marshall to kill Thraxxia. Marshall knew he didn't have a chance against the demon assassin, but his goddess gave him no choice. He briefly tried to fight, only have have his magic counterspelled by Myster E, who feared angering his patron. Thraxxia commended Myster E for his loyalty before mocking and ruthlessly beating Marshall, who found himself stripped of his cleric magic by Waukeen for what the goddess perceived as his failure.
When Myster E finally figured out he was becoming a hexblade rather than wielding one, Thraxxia appeared before him to claim her prize. But she was unaware of the power Myster E had gained through a wish from a noble marid and soon found herself on the defensive. She opened a portal to the Abyss, retreating to her demon allies to gather them against the adventurer. But before she had the chance, Myster E pursued her and struck a fatal blow just as she reached her allies. Seeing their demonic mistress, a child of Graz'zt, killed before them, the demons fled as Thraxxia died a true death from being killed in her home plane.

After the Quest for the Quintus Gems Campaign

When Rhith suggested Graz'zt as a potential ally against █████, Lady Kemlar had Thraxxia resurrected to act as an emissary to her father. To curry favor with both demons, Lady Kemlar had Myster E brought before Thraxxia and executed him, presenting the warlock's head to her as a "gift". All she asked in return was that Thraxxia tell Graz'zt that she and Rhith sought an audience. Thraxxia used her magic to turn Myster E's cadaver into a new sword, a hexblade, for herself while also claiming the Black Quintus Gem.
While Graz'zt was displeased with Thraxxia's initial failure with Myster E, he was nonetheless pleased to have his prized assassin back and better than ever. Though Thraxxia was not present for Lady Kemlar and Rhith's meeting with her father, she was informed after the fact that she would be the one to facilitate relations between their two factions. At least until █████ had been destroyed.

Current Status

At her father Graz'zt's court, the Argent Palace

Circumstances of Death

Stabbed by Myster Eazy E during her attempt on his life (later revived by Lady Kemlar)