MCU: 8 Villains Who Could Be The Next Big Bad
1. Dormammu
Doctor Strange saw the introduction of Dormammu to the MCU as a cosmic entity with enough power to destroy worlds. There is certainly a hint to the strength of Galactus in this iteration of the villain and such is his might that he could not be defeated by pure strength. It took the Time Stone for Strange to overcome his threat.
Are we supposed to believe that a being such as this will stay away from Earth simply because he promised to?
Dormammu will have retreated to The Dark Dimension after his encounter with the Sorcerer Supreme, but his eyes will not have left Earth. As soon as he has a plan to relieve Doctor Strange of The Time Stone, and the world is vulnerable, he will attack. There will be no better time for this than after the final battle with Thanos. The team will be battle-weary, broken, and possibly a few members lighter.
As with Thanos, this fight would affect every single hero in the MCU, but would also give Doctor Strange centre stage going forward. Since he has already battled with Dormammu he would assume a much needed leader role for The Avengers with the potential lack of Iron Man or Captain America to march behind.
With Dormammu we would have a villain more than worthy of the title of 'big bad', particularly if the fight is taken into his Dark Dimension.