Avengers: Endgame: 15 fan theories so crazy, they might be true
By Mark Lynch
11. The return of the Dread Dormammu
In the Doctor Strange movie, Stephen Strange tricked Dormammu into never coming back to Earth. Now that Doctor Strange is no longer with us, Reddit user /u/ak2usp points out that the deal Strange and Dormammu had may be off. With rumors circulating that there’s a bigger threat to the Universe than Thanos, it’s a safe bet to pick Dormammu as a big bad that could challenge Thanos. Even if he does have the power of the Infinity Stones. They also point something out that may have gone unnoticed:
"“It’s possible that Thanos snap somehow opened a gateway for the ruler of dark dimension and to his most advantage there are no sorcerer supremes left to guard earth from him.”"
Crazy Scale: 8
As it was mentioned earlier, Thanos may not be the only big bad in Avengers: Endgame. Anyone with dreams of ruling the Universe may be coming for Thanos. Among those beings is Dormammu.
He’s spent countless millennia trying to come to this realm only to be stopped by the Sorcerer Supreme. There’s no better time to try to make another play than now. One thing that Dormammu may not count on is Thanos taking him out. Allowing Dormammu and his demons to crossover defeats his purpose of culling the universe. Thanos is too smart to not think of other realms testing his might.