Guardians of The Galaxy
In the alternate future of the Guardians of the Galaxy, Dr. Strange assumed the title of the Ancient One (previously held by his mentor) and took on a disciple of his own, a Lem named Krugarr. Strange/the Ancient One was eventually killed by Dormammu, who was defeated by the combined efforts of Krugarr, his disciple Talon and the Guardians.
Read more about this topic: Alternative Versions Of Doctor Strange