Dormammu

"He is the Cosmic Conqueror, the Destroyer of Worlds. A being of infinite power and endless hunger, on a quest to invade every universe and bring all worlds into his Dark Dimension. And he hungers for Earth most of all."

- Wong

Dormammu is a primordial, inter-dimensional entity who wields apocalyptic levels of supernatural power and is the ruler of the Dark Dimension. Dormammu convinced Kaecilius to use his power to destroy the Masters of the Mystic Arts and bring the Dark Dimension to Earth. Before Dormammu could complete his plans, he was confronted by Doctor Strange, who used the Eye of Agamotto to trap Dormammu in an endless time loop until he agreed to leave Earth and take Kaecilius with him.

Deal with the Zealots
"Learning of an infinite Multiverse includes learning of infinite dangers. And if I told you everything else that you don't already know, you'd run from here in terror."

- Ancient One to Doctor Strange The primordial creature known as Dormammu is a trans-dimensional life form that lives within the Dark Dimension. Wielding frighteningly tremendous supernatural power of apocalyptic proportions, Dormammu seeks to conquer every dimension of the Multiverse, including the Earth. To achieve this, he managed to employ contact with Kaecilius, a rogue member of the Masters of the Mystic Arts who had become disillusioned with the Ancient One's ideals. The two struck up a deal, with Kaecilius agreeing to gather the necessary items to enable the Dark Dimension to come to Earth.

Meeting Doctor Strange
"You will never win." "No, but I can lose again. And again, and again, and again, forever. And that makes you my prisoner." "No! Stop! Make this STOP! Set. Me. Free!"

- Dormammu to Doctor Strange

As they had planned, Kaecilius destroyed two of the three Sanctums and finally with the Hong Kong Sanctum now vulnerable, Dormammu was now free to do as he had always desired, to fuse the Dark Dimension with Earth and destroy it. However, Doctor Strange, a new member of the Masters of the Mystic Arts, flew into the Dark Dimension to confront him, claiming he had come to bargain for Earth's protection. Angered at this, Dormammu quickly killed Strange by blasting him with energy, but to his confusion, Strange reappeared on the Dark Dimension surface, repeating himself. Perplexed, Dormammu killed Strange again only to have him reappear, repeating his intention. Stunned, Dormammu demanded to know what was happening; the Doctor revealed he had used the Eye of Agamotto and the Infinity Stone hidden inside it to create an infinite time loop and intended to force Dormammu to relive the moment of killing Strange forever unless he agreed to his demands. Enraged, Dormammu killed Strange again, only for him to return again. Strange explained that this was the only trap Dormammu could not escape from, since the Dark Dimension was a place beyond time itself and therefore Dormammu had no power over it. Dormammu continued to kill Strange repeatedly until he couldn't stand the entrapment any longer and began begging Doctor Strange to end the time loop, which he did, on the condition that Dormammu banished himself and the Zealots from Earth forever. Dormammu did this, while also turning the Zealots and Kaecilius into Mindless Ones and dragging them into the Dark Dimension to live in agony forever, and kept his own word, sealing the portal between the dimensions.

Personality
"Dormammu, I’ve come to bargain." "You’ve come to die. Your world is now my world, like all worlds."

- Doctor Strange and Dormammu

Dormammu is nothing more or less than the ultimate personification of destruction, megalomania, and ruthlessness. He appears to be a being of pure and utter malevolence, seemingly focused only on his own "mission" of expanding his Dark Dimension realm and conquering all other worlds and dimensions of the Multiverse, in order to fuse them in as well, recruiting Kaecilius and the Zealots to help him do this, claiming that it would grant them everlasting peace which they all desired. Dormammu takes pleasure in causing pain and suffering, delighting at the chance of killing his enemy, Doctor Strange, until realizing that he was stuck in an endless time loop.

Despite his ruthlessness, Dormammu seems to be somewhat honorable, as seen by his keeping his end of the bargain when he agreed to end his assault on Earth and never return if Doctor Strange broke the loop.

Powers
"Just as you gave Kaecilius power from your dimension, I've brought a little power from mine. This is time. Endless... looped... time."
 * Dark Dimensional Manipulation: As the absolute ruler of the Dark Dimension, Dormammu has absolute control over the Dark Dimension, with the dimension itself warping to form his face and even form other body parts, such as a hand. He uses the dimension's power as a weapon, utilizing it to constantly kill Doctor Strange over and over again, either with energy blasts or by manipulating the very ground he stood on, when the latter trapped him in an infinite time loop using the Time Stone. His influence also stretched beyond the confines of his realm to those who used his power, such as the Zealots, which caused their deformities. He was also able to rapidly turn his followers into decayed, fossil like figures with glowing red symbols of the Dark Dimension on their heads, before making them fly up into the Dark Dimension.

- Doctor Strange to Dormammu


 * Power Bestowal: Dormammu bestowed mystical powers to Kaecilius and his Zealots from the Dark Dimension, making them powerful enough to challenge the strength of the Ancient One herself. They notably gained the ability to fold space without being inside the Mirror Dimension, which allowed them to form Space Shards. However, his bond to his followers also allowed him to absorb them into his Dark Dimension at will, causing them to rapidly turn into decayed, fossil like figures with glowing red symbols of the Dark Dimension on their heads.
 * Superhuman Strength: Dormammu possesses immeasurable levels of strength due to his size and spacial warping abilities, shown when he manifested a colossal hand to easily crush Doctor Strange as if he were an insect.
 * Immortality: The Dark Dimension is a timeless entity, thereby resulting in Dormammu being a primordial immortal, with the Ancient One describing him as a precursor to time itself.

Allies

 * Zealots - Servants
 * Kaecilius
 * Lucian †
 * Blonde Zealot
 * Brunette Zealot
 * Tall Zealot †

Enemies

 * Masters of the Mystic Arts
 * Agamotto †
 * Ancient One †
 * Stephen Strange/Doctor Strange † - Victim (multiple times)
 * Wong
 * Karl Mordo

Trivia

 * In the comics, Dormammu was a Faltine sorcerer who left his original dimension and became the ruler of the Dark Dimension. He once enlisted Baron Mordo as a servant to fight Doctor Strange. He and Odin play chess to determine the fate of the Universe, but the games end in a stalemate to maintain the balance between Chaos and Order.
 * It was Benedict Cumberbatch's idea to perform motion-capture for Dormammu, as he felt that the character should be an evil reflection of Doctor Strange.

Behind the Scenes

 * Benedict Cumberbatch was only credited for portraying Doctor Strange in the film. The fact that he also portrayed Dormammu was revealed by Scott Derrickson in an interview with . Cumberbatch's voice was blended with another actor's, to make it harder to tell it was him. The director said he was unable to recall who the other actor was, only that he was also British.
 * The producers of Doctor Strange asked to do a recording session for Dormammu, because they wanted another voice as an alternative to Cumberbatch, but they went back to their original choice eventually.