Phaia

Phaia was a Red Wizard of Thay in the Doomvault dungeon in the 1480s DR.

Personality
Phaia was a true believer of Szass Tam. She was also opportunistic and self-obsessed like her master, even ready to betray him to save her own life. Phaia believed that no magic was too dangerous and no experiment too dark if it provided power for herself.

History
Phaia was a Red Wizard assigned to the secret complex of Doomvault under Thaymount. She was a subordinate of Lahnis, but also there to guarantee the loyalty of her superior to Tam's cause.

In the 1480s DR, she was tasked with draining the soul of a prisoner, Kelson Darktreader, in order to power undead creatures. When the heroes of Daggerford arrived, Phaia fought them and was defeated.

Behind the scenes
Although not easy, she can be convinced to betray Tam in exchange for her life. She can give the players some useful information and even possibly resurrect Kelson when he eventually dies. In that outcome, she readily escapes from Doomvault.