Mordo tumbled through the planes of existence after failing to open the Chaos Gates. This made him more powerful, and he started spying on Strange, waiting for the right time to strike. A woman named Morgana Blessing started flirting heavily with Strange, and Mordo made it seem as though she had some kind of magical spark in order to get Strange to investigate her. Mordo hid in her mirror and attacked Strange, who initially thought Mordo was in Blessing’s body. Strange hid in Blessing’s cat after the onslaught, and then blasted Mordo.
Two can play that game, though. Mordo killed Blessing’s cat and took its place. He hid in her bag and waltzed into the Sanctum Sanctorum, kidnapping both Clea and Blessing. He took them to Stonehenge and then went back into time, to World War II-era England. There, his grandfather Heinrich Krowler was waiting, as the real power behind this was revealed: Dormammu.
Dormammu planned to enter Earth from the past, using Krowler’s body as his host, Clea as his sacrifice, and Blessing’s body to house Mordo. Strange cleverly attacked the Dormammu of that era and timed it such that he channeled the older Dormammu’s energy against the present one, destroying his host body. Clea had cast a love spell that disrupted the hate sustaining the ceremony, allowing Strange to strike. Once again, Mordo was someone’s pawn, and once again, he was blasted to bits for his efforts.