Tiamat dominates the mind of those who are devoted to her as Priests of Tiamat, either through their own frailness of mind or a parallel of thought. Sephira is a person after Tiamat's own heart.

Pursuit of power through dominance is appealing to someone who squirmed underfoot of a cruel master. Sephira Brittlebane was captured from an insignificant village deep within the mainland by one of the vile clans of drow. Her family, friends, and community members all suffered a horrible fate as slaves to these foul-minded people. But as the days turned into months, and months into years, Sephira's character changed. Once a soft-spoken, charitable girl, exposure to cruel brutality, manipulation, and exploitation poisoned her mind with vile thoughts of her own: vengeance, violence, and hate.
One day, Sephira accidentally cast a cantrip spell which scarred one of her masters; she had no idea that she had the ability to cast magic. She was punished thoroughly for it, and has a scar from it. However, this moment sparked a flame within Sephira's heart, this could be her way to escape. And to get revenge. She waited, honing this newfound power of hers, and subtly influenced her masters into giving her more and more information she needed. Finally, the day she had planned for years arrived. Leading a group of slaves, she swiftly eliminated the defending guards of the drow settlement using traps. Afterwards, she led the mob throughout the town, slew her slavemasters, and then proceeded to slaughter the slavemaster's families and leave their settlement in the Underdark demolished. The magic she used was sinister, a reflection of the transformation that had happened to Sephira.

Sephira rose to leadership through her own force of will and surprising strength. And with an axe to grind against all drow, she seeks to never be weak again, for fear of the helplessness and pain she endured as a child would return. Once she reached the surface of Faerun, Sephira used violence, manipulation, and fraud to amass wealth as a mercenary guild disguised as a brothel. Her gained the interest of the Cult of the Dragon, who were impressed by her shrewdness, cunning, but most of all her magic. She sought power, and that is what the Cult of the Dragon offered her.

Now, Sephira operates as one of the Cult's Priests of Tiamat. She allowed herself to submit to the ritual, knowing the momentary lapse of weakness was necessary for further strength. Her magic potential has swollen since then, and her appetite for domination has not been satiated. She was entrusted with the Red Dragon Mask, which Sephira found to be comedic irony. She slew those drow because they wronged her and she was better than them. She used others for her gain because she could. And she will use the Cult of the Dragon as her means of attaining even greater heights. Truly, she bears the soul akin to that of a dragon.

She wields tremendous power, through the combination of her innate sorcerous magic, devilish cunning, and the enhancement of the Dragon Mask and the status as a Priest.