Karl Amadeus Mordo is a former member of the Masters of the Mystic Arts and was a close ally to the Ancient One, assisting in recruiting and training their future sorcerers. When Mordo had encountered Stephen Strange, he invited him inside Kamar-Taj, despite the Ancient One's objections, and had later aided him with the conflict against Kaecilius and the Zealots. During this battle, Mordo learned that the Ancient One drew all her power from the Dark Dimension, which was forbidden to the Masters. Following the death of the Ancient One and the eventual defeat of Kaecilius, Mordo was so mortified by his colleagues' constant violation of natural laws that he turned his back on his allies. Instead, he chose to restore balance by stripping sorcerers of all their powers.