Former Sorcerers Supreme from Earth-616
Sorcerer Supreme or Sorceress Supreme is a title granted in the fictional Marvel Universe to the "practitioner of the mystic or magic arts who has greater skills than all others or commands a greater portion of the ambient magical energies than any other organism on a given world or dimension". By definition, there can be only one Sorcerer Supreme per world at a time. It is said by Rick Remender as "the most powerful rank in the universe."
Doctor Strange was the most recent Sorcerer Supreme, and has been almost continuously since the transcendence of his mentor, the Ancient One, later reaffirmed when he was the winner of the Trial of the Vishanti. It has recently been revealed however that having failed in his duties, Strange no longer holds the title, having decided to pass on his duties for another of a purer heart. Jericho Drumm is the current Sorcerer Supreme, despite his lacking in knowledge of outer fields of magic beyond his own, due to his soul being the most pure and deserving, appointed the title by the joint choice of the Vishanti and the Ancient One.
During Dark Reign, a new Sorcerer Supreme will be chosen. An image on Comic Art Community depicts Dr. Strange returning in New Avengers #51 and possible replacements for the position of Sorcerer Supreme. Possible candidates include: Brother Voodoo, Doctor Doom, the Hood, Nico Minoru, Magik, the Ghost Rider, Wiccan, Druid (the son of the late mystic Doctor Druid), Baron Mordo, Ian McNee and Scarlet Witch (or possibly the Asgardian Loki in her guise), Storm, Clea, Spiral, Selene, Agatha Harkness (unclear whether deceased or still living) and even Dormammu. Though Daimon Hellstrom and Jennifer Kale were both deemed suitable candidates, it appeared that they were not destined to hold the title, and instead united to confront a threat so deadly it is worthy of a Sorcerer Supreme to handle. Marvel has described the candidates on its own official website, (as well as in interviews), as well as stating the pros and cons of each one.  Clea is said by Marvel to be the most likely candidate thus far for the role of Sorceress Supreme of the Marvel Universe, with the odds of 5-1.  Formerly, during the Trial of the Vishanti, Khalid Inshallah, Jules St. Thomas, "Screamer," Sen-Yu, Tareva, and Wai Chee Yee, along with at least four other unnamed mystics were also deemed worthy candidates for the office, chosen as most learned in the ways of sorcery by the Aged Genghis.
The new Sorcerer Supreme has been chosen in New Avengers #54. The Eye of Agamotto automatically displays to Strange and the New Avengers through its arcane powers in the Quinjet at least thirty-five images of "those who would replace" Strange, suspended in floating and shimmering blue bubbles of light, before the Eye itself vanishes from Strange. At the end, after Dormammu, the Hood and their forces work to attack the New Avengers, the Son of Satan and Doctor Strange, the new Sorcerer Supreme of the Marvel Universe is revealed at last to apparently be Brother Voodoo, the Haitian Houngan Supreme who has worked with Strange in the past, who now bears the Eye as a symbol of his new position and intervenes with a potent display of his own fire power.
The new Sorcerer Supreme has been shown to be benevolent in nature, as Dormammu has mentioned to the Hood in the second issue of the controversial Marvel Zombies 4 (into the Dark Reign of Earth) that the spells of Earth's Sorcerer Supreme bar him from entering their plane, thus confirming neither the Hood nor Dormammu received the title; as Strange lost both the title and the power to maintain or work such spells long before the Reign, this refers to the new Sorcerer Supreme. However, the new Sorcerer Supreme still has "a lot to learn" and must learn what he requires from Spider-Man, ruling out Doom, Mordo, Loki, Harkness or Clea as the new Sorcerer Supreme. 
Past Sorcerer Supremes include the ancestor of Sebastian Shaw: Reverend Hiram Shaw; and the ancestor to Ororo Munroe, Ayesha of Balobedu. Following the demon Zarathos's defeat some twenty-five millennia ago by the supernatural Blood, some among them worshiped him as the Fallen. Salomé, possibly the ancestor of namesake of the millennia old line of sorceresses of the same name, was among the Fallen's most powerful members, and around the thirteenth century B.C. she became Sorceress Supreme, by her account the first denizen of the Earth to do so. She presumably protected the Earth dimension from various threats, but her ego demanded worship as a goddess, which she received in the Assyrian city of Nimrud. Eventually, Salomé and her fellow Fallen were banished to another dimension, while the Sorcerer Supreme role apparently fell to a sorcerer on another planet within Earth's universe, though eventually the responsibility fell again on the burdens of the mystics of Earth. Another past African Sorcerer Supreme, Makeen, was shown accompanying former Houngan Supreme, Legba, in the "six hundredth and sixteeth Age of Man" (apparently 616 A.D.) to prevent the Voodoo god Ogoun from invading the Earthly plane, eventually sacrificing their "living souls" to seal the gateways and turning their physical forms into statues which stand to this day; the Eye of Agamotto and Cloak of Levitation then together leave Makeen for their next master, the new Sorcerer Supreme. According to Doctor Strange, the demonic, tentacled Marrakant Hellguard, resistant to Strange's magic, has incinerated every other Sorcerer Supreme since the 1500s (though apparently before the Ancient One's time holding the office) that has confronted it, only to be slain by Strange using Hitler's Handgun, designed to be effective in disposing of mystically-powered opponents.
The Vishanti are apparently the ones who select the current Sorcerer Supreme of the Marvel Universe, as it was they who gave great magical power to the Aged Genghis shortly after humanity's dawn in return his summoning together the greatest mystics in the world every century for a tournament to determine the Sorcerer Supreme, affirmed by the Vishanti themselves. The Vishanti were also the ones who stripped Strange of the Sorcerer Supreme title in the past and, while finding her repulsive, made Salomé Sorceress Supreme once again. Strange competed against a dozen others, including Doctor Doom, to retain his own position, and ultimately triumphed. The Vishanti has rarely been called upon for power by those other than the Sorcerers Supreme Doctor Strange and the Ancient One, and, on one instance, Clea, Strange's disciple. When Mockingbird asked Doctor Strange whether a "bad" person (or, as Strange says, one who abuses the magics for personal gain), by the context of their society, could possibly obtain the office, Strange replied that, "Good, bad, they have no real meaning here...not in this context."
The Sorceress Supreme of the Dark Dimension, the realm to which Dormammu had been banished, is Clea, disciple and lover of Doctor Strange. The current Sorceress Supreme of the demonic Limbo, is Illyana Rasputin aka the mutant Magik. The Sorcerer Supreme of the Purple Dimension, a less well-known pocket realm based in old Doctor Strange stories, where green-skinned humanoids abduct humans as slaves, is Aggamon. The Sorceress Supreme of the Winding Road (and former Sorceress Supreme of Earth) is Margali Szardos, a sorceress with power enough to proclaim herself as the Sorceress Supreme. Tiboro is the Sorcerer Supreme of the Sixth Dimension, and owns a strangely-shaped wand that fires an ecto-plasmic ray, powered by lightning. Necrom is the Sorcerer Supreme of his Earth in a reality alternate to that of the mainstream one, known as Earth-148 (Ee'rath). Shanzar is the Sorcerer Supreme of the Strange Matter dimension, a mystic realm visited by Doctor Strange. An alternate version of Hank McCoy has been shown to hold this office in a reality also affected by Wanda's magic.
As has been stated many times by various characters, there cannot be any permanent Sorcerer or Sorceress Supreme of a dimension/reality; eventually the office would pass on to another, with one's will or without. However, one could be a master of the mystic arts (such as Baron Mordo or Morgan le Fay) and not hold the title. Each existent reality of the Marvel Multiverse appears to be defended by a Sorcerer or Sorceress Supreme, though certain dimensions linked to each reality does not (such as Asgard or Olympus). Urthona was the Sorcerer Supreme of his home planet Gevaltu within the Earth-616 dimension, but sought to become the Sorcerer Supreme of the entire universe by overpowering the one that currently held that position, Doctor Strange, though his efforts eventually failed.
The Lord of the Vampires before Dracula rose to power, Varnae (once summoned to the Assemblage of Avatars, a gathering of the most powerful users of magic existent on Earth at the time, including the then-Sorceress Supreme Zhered-Na, by the first Sorcerer Supreme Agamotto to seek a solution for the conflicts between the Elder Gods, but little was achieved during the meeting and Agamotto himself grew frustrated by the limitations of humanity), one time while battling Doctor Strange, has claimed that he once sought the title of Sorcerer Supreme before he became a vampire.
The Sorcerer or Sorceress Supreme is functionally immortal, having the immortality conferred upon him after assuming. Such a being with the role does not age nor succumb to medical diseases, after a trial with Death, which you are forbidden to fight evoking the power of the Vishanti, (in which one does not truly destroy death itself, but truly accepts one's own mortality), though he can be killed; the Sorcerer or Sorceress Supreme has access to the near-unlimited power of the Vishanti, the Octessence, and various other Principalities, as well as granted possession of such powerful mystic items ("gifts") as the Eye of Agamotto, Orb of Agamotto, Wand of Watoomb and the Cloak of Levitation, along with "books of knowledge" to help the Sorcerer Supreme train for his or her quests, such as the Book of the Vishanti.
There exists an ancient line of humans trained to serve the current Sorcerer or Sorceress Supreme of many of the realities in the Marvel Universe; Wong served Doctor Stephen Strange, Sorcerer Supreme of the Earth-616 reality, for years before Strange failed at long last in his duties as his dimension’s protector and lost the station; other Wongs exist in other parallel and alternate universes as well.
It appears possible that holders of the position of Sorcerer or Sorceress Supreme in other universes or dimensional planes are capable of becoming candidates for the Marvel Universe's. Dormammu has also claimed destroying the most recent Sorcerer Supreme would grant the killer the title in his stead. The Eye of Agamotto, along with other magical objects, are not automatically removed or given to the new Sorcerer Supreme or candidates even after the former one has fallen from the station.  The Sorcerer Supreme can also "surrender," "lose" or "bestow" his position upon others of worthiness (as well as inheriting it from the former Sorcerer Supreme), though is also capable of taking it back multiple times after such a loss, as Strange has done various times in the past. Taking back the office has also been accomplished by Salomé of the Fallen, even without a contest between the universe's major power mages. One can become a Sorcerer Supreme against one's will, as shown in on a What If? divergent reality of Earth, as done to Stephen Strange by the dying Doctor Doom, though conventionally and under normal circumstances, one must first consent to accept the challenge and the responsibilities coming with the station, as voiced by the Ancient One and Agamotto through the Eye. Religion also does not appear to be a significant factor in the determination of the role of Sorcerer Supreme, as made evident when Brother Voodoo, of the Haitian faith, was chosen by the arcane deity Agamotto through his Eye and the spirit of the Ancient One, despite Drumm's worship of the Loas; in fact, the presence of Voodoo's spirit brother also appeared to be included in this responsibility, instead of a hindrance in the selection. Once, on Earth-148, the Sorcerer Supreme Necrom, while holding values opposite to those of most other Sorcerers Supreme, even worked with the dark arts, including necromancy, apparently indicating not all Sorcerers Supreme throughout the Marvel Multiverse must be pure in order to hold the title. There is also some kind of sign, test or initiation one must survive (though survival is not guaranteed, even if one is chosen for the office) to truly take up the mantle of Sorcerer Supreme. It is possible for even moderately proficient mages to steal the magical powers of a Sorcerer Supreme against his will, as Nicodemus did to Doctor Strange; however, one must also possess considerable mental discipline as the Sorcerer Supreme, or else one would be overwhelmed by the sheer power and vast mystical awareness that belonged to one with such a title. Never before has the Houngan Supreme of Haiti served as the Sorcerer Supreme before Jericho Drumm. 
Despite numerous statements that the Sorcerer Supreme is only to defend one world, his duty is actually to the whole of the dimension the world is within; Doctor Strange was the Sorcerer Supreme of the Marvel Universe, yet was often, erroneously, called only “Earth’s Sorcerer Supreme,” likely used by writers and editors to limit his power as to not enable him to diffuse every negative situation he or other characters were confronted with, as stated once by Marvel editor Joe Quesada, who admitted the difficulty of placing Strange in a truly “dangerous” situation. While it is certainly possible to have more than just one master of the mystic arts in one dimension, only one of them can hold the title Sorcerer Supreme at a time. More supporting evidence of this can be given by the fact there is no other known Sorcerer Supreme on any of the planets not of Earth; for example, there are at least tens of thousands of alien worlds in the Marvel Universe, many known to have potent mystics, yet none were called the Sorcerer Supreme. Furthermore, the mysterious cosmic being the Stranger, after revealing himself to not be the Beyonder, while describing the high potential, power and uniqueness of Earth (including the manifestation of the Phoenix Force there, the repelling of such awesome beings as Galactus and the involvement of the Kree, Skrull and Shi'ar Empires there for so many times), says “the Sorcerer Supreme makes his home there” and when Strange was captured once during the days of the Defenders, Strange was said to be the Sorcerer Supreme of their “cosmos,” strongly implying that the Sorcerer Supreme is not limited to his home planet, but the entire universe he resides in, for a defender of one mere world out of perhaps millions in the universe would be negligible indeed to one of the most powerful cosmic entities in existence.
House of M
In the House of M reality shaped by the chaos magic of Wanda Maximoff Warren Traveler, a man who in Earth-616 never fell down the dark path that would lead to his becoming a powerful magician, was Sorcerer Supreme. He was an enemy of Ms. Marvel, then going by the name "Captain Marvel", and later appeared in her current ongoing title slightly mad from the shift in reality while he warped from their last encounter.
Professor Imam is the Sorcerer Supreme of Earth 712, the home universe of the Squadron Supreme. He appears in the Squadron Supreme: Death of a Universe graphic novel. He was able to predict that Arcanna's son Benjamin Thomas Jones, aka Mysterium, was destined to become the next Sorcerer Supreme. After the events of the graphic novel it is unknown if Benjamin is able to take up this role of Sorcerer Supreme.
In the alternate future of the MC2 universe, Doctor Strange has retired from the role and the new Sorcerer Supreme is the young Doc Magus (Dormagus) who now has the Eye of Agamotto. Strange is still a practicing sorcerer, however.
In this reality, since Stephen Strange never showed up in Tibet, having decided to work for SHIELD in exchange for them restoring his hands with claws similar to Wolverine's to take over as The Ancient One's apprentice, Mordo arose to the title of Sorcerer Supreme after being mystically tutored. His moral ambiguity caused his death when he eventually had to face Dormammu.
Age of Apocalypse
In the "Age of Apocalypse" parallel universe Brother Voodoo replaced Doctor Strange as the Sorcerer Supreme. He battles Dormammu and also helps in Apocalypse's defeat. However, he vanishes when the Eye of Agamotto is taken away from him.
In Marvel 2099, one possible future of the Marvel Universe, the Sorcerer Supreme of Earth is a young woman calling herself "Strange (Earth-928)". She is so inexperienced in her powers and uses them so recklessly that once caused the death of her brother. She secretly shares her body with a monstrous demon and her main opponent is Garokk.
In the Parallel universe series Earth X, Clea has betrayed Doctor Strange and has killed him at the behest of her lover, Loki, becoming the Sorceress Supreme of that reality. She is discovered by Bruce Banner, and Thor takes her away and imprisons her in Asgard.
Guardians of the Galaxy
In the alternate future of the Guardians of the Galaxy (Earth-691), Doctor Strange took the title of Ancient One (previously held by his mentor) and also took on a disciple, a Lem named Krugarr. Dormammu murdered The Ancient One (Doctor Strange). Dormammu was eventually defeated by the Guardians, Krugarr, the new Sorcerer Supreme, and his disciple Talon.
Earth-Callisto Sorceress Supreme
A reality where Callisto was the "Mistress of Mysticism" and the Sorceress Supreme, holding the Eye of Agamotto and the Cloak of Levitation, being the mistress to Ororo Munroe, and where Callisto battled the Exiles.
In this reality of anthromorphic animal versions of Marvel characters, a monkey version of Doctor Strange held the position of Sorcerer Supreme before perishing and passing the title onto Cleook, Sorceress Supreme.
In many of these What If? alternate realities, showing parallel Earths exactly the same as the mainstream Earth-616 dimension until at some point a different event took place causing a divergence point in the timestream, there is either a different Sorcerer Supreme, or Doctor Strange is the Sorcerer Supreme albeit with various differences from the mainstream version.
Earth-938 (What if Doom became Sorcerer Supreme) When Doctor Doom failed to rescue his mother's soul from Mephisto, he sought out the Ancient One to learn the mystic ways and attempt once again. After failing to retrieve his mother from Mephisto's grasp on his own, Doom seeks out the Ancient One in order to learn the Mystic Arts and once again attempt to rescue her. Along his way, he becomes more powerful than Mordo, and when Stephen Strange shows up with his crippled hands, instead of guiding him on the spiritual path, Doom cuts off his hands and replaces them with mechanical ones to increase his accuracy and surgical abilities. In his second attempt at freeing his mother's soul, Doom and the Ancient One defeat Mephisto and rescue her, at the price of the Ancient One's death. Unprepared for the Ancient One's fall, Doom is unable to defend against The Dread Dormammu's attack on the Earthly plane. Knowing he's out powered, Doom enlists the help of the Fantastic Four to use his time platform and retrieve Blackbeard's treasure, an Obsidian Stone used by Merlin, which would help him defeat Dormammu. The Four accomplish their task and leave Thing back in that time to become the pirate, Blackbeard (at Benjamin Grimm's request). Upon their return, the world is overrun by demons, and The Avengers, The X-Men, Daredevil and Spider-Man are fighting them off in New York City while Doom battles Dormammu overhead. Reed manages to get the Stone to Doom in the nick of time, sending Dormammu back to the lands of Faltine, just after dealing a deathly blow to Doom. Ironically, Stephen Strange ends up being the doctor who attempts to save Doom's life, (on Tony Stark's dime), but cannot, and with Doom's dying breath, he instructs his doombots to abduct Strange and put him into his armor, overwriting his personality and memories to those downloaded from Doom, forcing him to become the next Sorcerer Supreme/Doom against his will. As Uatu says, "As Sorcerer Supreme, it can be said that Victor con Doom had both the most short-lived and long-remembered tenure of them all. For With both his endless scheming and his boundless ego, he assured that this world would always have a Sorcerer Supreme...and that Sorcerer would always be Doom!"
Earth-9810 (What If Tony Stark Became the Master of the Mystic Arts) Tony Stark becomes the Sorcerer Supreme of the Marvel Universe after Stephen Strange's hands are shattered in a ride he takes him along while drunk. Stark becomes the Ancient One's apprentice instead to battle Baron Mordo, who had magically silenced him from revealing his treachery against his master. Stark ends up combining his understanding of technology as well as magic to create an armor which incorporated both. Dormammu intends to set the Mindless Ones upon Earth to destroy it, and Strange, Clea and Stark unite to banish the Faltinian sorcerer. It held a vast storage of magical spells in its memory, ready to be deployed at a moment's notice. This armor was lost when Tony Stark sent it on an endless dimensional quest, carrying the body of the dread Dormammu, forcing the dark lord (in his astral form) to pursue it.
- ↑ http://www.comicartcommunity.com/gallery/details.php?image_id=31662&sessionid=8208862d0489425f68d3e33ce7e748d2
- ↑ 2.0 2.1 http://www.marvel.com/news/comicstories.7099.New_Avengers%7Ecolon%7E_Magic_Show
- ↑ http://www.comicbookresources.com/?page=article&id=20145
- ↑ New Avengers #55
- ↑ Marvel Tarot #1, June 2007
- ↑ Doctor Voodoo: Avenger of the Supernatural #3
- ↑ Doctor Strange: The Oath #4
- ↑ New Avengers #53
- ↑ Doctor Strange, Sorcerer Supreme #18
- ↑ New Avengers #52-54
- ↑ http://www.comicheronews.com/?p=620
- ↑ In search of Cleanex in What The--?! #19