A demonic spirit who was defeated and imprisoned in a cave many centuries before the events of the story, the Evil Witch of the Dark was accidentally released by DG and Azkadellia when they were children and took possession of Azkadellia. It is the corrupting influence of the Witch that causes Azkadellia to be evil. The Witch is shown communicating with Azkadellia at one point, urging her to continue her quest for the Emerald. The Witch tells Azkadellia, "I will never leave you", implying that Azkadellia suffers from a fear of abandonment. The Witch also has control over the Mobats who serve Azkadellia due to the presence of the Witch within her. At the climax of the series, when Azkadellia stands upon a platform using the power of the Emerald combined with her Machine to fix the twin suns of the OZ in a permanent eclipse, DG reaches out her hand and begs Azkadellia to accept it. After a struggle with herself, Azkadellia does take her sister's hand, and is freed from the Witch, who at this point assumes physical form without need of a host. The Witch tells DG to "Keep the little bitch", but quickly discovers that she cannot hold the Eclipse in place without the Emerald. Howling in rage, she demands that Azkadellia give her the Emerald. Instead, DG and Azkadellia link hands, insulating themselves within a magical circle of protection. Powerless to harm them, the Witch increases in size until she towers over the two princesses, screaming in fury. Meanwhile, DG's allies succeed in destroying the Machine. The Witch utters a final shriek, before finally melting, mimicking the demise of the Wicked Witch of the West in the original story, which she is heavily implied to be.
She is similar to the Amatsu Mikaboshi from Japanese mythology and the Swamp Witch from The 10th Kingdom. She also bears similarities to Palpatine from the Star Wars mythos in terms of personality and appearance. Her proclamation of "Ohhhh, the magic is strong in you" when encountering DG and Azkadellia for the first time is particularly reminiscent of a line spoken by Palpatine in Revenge of the Sith