The Skirmish in the Dark Dimension is a confrontation between Doctor Strange and Dormammu planned in order to bargain with the inter-dimensional entity to end his assault on Earth. Dormammu proceeded to kill Strange unaware that the sorcerer had trapped them in an endless time loop that repeated itself after Strange had been killed. As time kept repeating, Dormammu became more and more distraught until he plead to be set free. Strange agreed only if Dormammu removed the Zealots and swore to never try to attack the Earth again to which Dormammu angrily agreed to.
- "Temporal manipulations can create branches in time. Unstable dimensional openings, spatial paradoxes, time loops! You want to get stuck reliving the same moment over and over again forever, or never having existed at all?"
"They really should put the warnings before this stuff."
- ―Karl Mordo and Doctor Strange[src]
Having destroyed the London Sanctum and attacked the New York Sanctum, Kaecilius and the Zealots launched their final attack on the Hong Kong Sanctum. They found the sanctum protected by Wong and the Masters of the Mystic Arts. Wong was killed in the resulting battle and the Hong Kong Sanctum was destroyed. With the final sanctum destroyed, Dormammu began to absorb Earth into the Dark Dimension.
Using the power of the Eye of Agamotto, Doctor Strange was able to reverse time, bring Wong back and restoring the Hong Kong Sanctum. Kaecilius returned and confronted Strange, telling him that his actions were useless. Upon hearing from Kaecilius that the Dark Dimension was "beyond time," Strange figured out a way to defeat Dormammu and headed directly into the Dark Dimension.
Entering the Dark Dimension, Doctor Strange came across Dormammu, who manifested as a warped version of the former neurosurgeon's face, and stated that he had come to bargain. Claiming that he had come to die, the entity killed Strange only to watch as he came back to life and repeated his previous statement. While confused, Dormammu killed Strange again only for him to reappear. Strange proceeded to explain that he used the Eye of Agamotto to create a loop that trapped them in the same moment.
Dormammu warned Strange he would suffer for eternity, to which Strange accepted. After killing Strange several times only to watch the loop reset, the desperate entity begged Strange to release him from the loop. Strange refused, firmly stating that he had come to bargain, and promised to break the loop on the condition that Dormammu put an end to his conquest and take the Zealots with him. The entity agreed to the demands, prompting Strange to leave the dimension and return to the battle.
The Bill Comes Due
Returning to Earth, Doctor Strange watched as the remaining Zealots were turned into Mindless Ones and transported to the Dark Dimension. Strange proceeded to reactivate the Eye of Agamotto and finish restoring the Sanctum before allowing time to resume.
As Strange and Wong began celebrating their victory, Karl Mordo began comparing Strange's abuse of power to the Ancient One's actions, blaming the Masters for the world's imbalances. He then stated that the bill would come due for them all and walked away from his former allies.
The New Protector
Sometime later, Doctor Strange realized he was not ready to harness the Eye of Agamotto and brought it back to Kamar-Taj. Wong agreed with his decision before noting that the New York Sanctum still needed a new protector and that Earth was now vulnerable to interdimensional threats. Stating that the Masters would be ready to face said threats, Strange returned to New York City and began serving as protector of the New York Sanctum.
Too Many Sorcerers
When Pangborn, who claimed he was using his own power, attacked him with a crowbar, Mordo easily overpowered his former ally before stripping him of his powers and causing his paralysis to return.