

From Sofiyan- Marvel
Now that Dormammu has made an appearance, we can probably expect him to resurface in a future MCU film, despite Stephen Strange banishing Dormammu to the Dark Dimension forever. ... However, Dormammu found a loophole in the deal: if Stephen Strange were dead, he wouldn't have to keep it.
It has been said that a “fully-fed” Galactus is around as powerful as Eternity itself and if this were true, then a fully fed Galactus would indeed be more powerful than Dormammu.
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Dormammu would simply pop Thanos into his universe. The Infinity Gauntlet doesn't work there and Dormammu would squash Thanos. It would take the combined power of the Gauntlet and all 6 Infinity Stones to resist Dormammu's power in Thanos' universe. With the complete set, Thanos can probably beat Dormammu in the MCU.
However, his bond to his followers also allowed him to absorb them into his Dark Dimension at will, turning them into Mindless Ones. ... 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.





