In the anime, the Shadow Lord revives Thaegan through her ring after a rat brought the item to him. Fully restored after the events at the Shifting Sands, Theagan finds her remaining children so they get revenge, recruiting Hot, Tot, Fie, and Fly to bring Lief's group to her. However, after being aged by the lapis lazuli and accidentally killing her four children, Thaegan is killed off by Lief cutting her ring finger off with her ring taken by the group to ensure she is not revived again. However, Theagan is revived again by the Shadow Lord, who motivates the sorceress with fear of her beauty being ravaged if she fails him again. Using the Mirror of Fear she received, capturing them after their hardship in the Maze of the Beast, Theagan attempts to torture Lief's group before murdering them once and for all. However, the plan failed as Shadow Lord's curse takes effect with Thaegan losing her magic while the spell that kept her youthful is broken as she reduced to an old corpse hag. She refused to live on in this state and decided to kill herself with what little magic she had remaining, unexpectedly taking most of her remaining offspring with her as she spent her final moments expressing motherly love to them and the spirits of her deceased children.

(Source: Wikipedia)