At one point during his training, the Ancient One had told him not to piss off the Master of Death. Stephen would have totally heeded the warning, had she told him who the Master of Death actually was. (Harry/Stephen).

Stephen Strange failed to figure out how to stop Dormammu with the time loop and as he was about to die from a mortal wound from Kaecilius, the Eye of Agammoto sent his soul back in the 1970's, inside a body of his relative named…Snivellus? And why is he being hung upside down? (Not a full fanfic, just a idea for whoever wants to adopt it!) it! Dr. Strange/Harry Potter crossover.