The Mandarin

Demand for a fourth Iron Man movie is obviously high. Robert Downey, Jr.’s character is by far and away the most popular hero in the Marvel Cinematic Universe, and a movie in which we finally get to see the character’s arch-enemy from the comic books would be most welcome – and it’s very likely to happen.
The Mandarin was fundamentally, infamously, and controversially changed as a concept in 2013’s Iron Man 3, when he was revealed to be a British actor performing a ruse, while Aldrich Killian went about his terrorist activities undisturbed – but the Marvel One-Shot entitled All Hail the King revealed that the “real” Mandarin is out there, and he’s extremely annoyed about the aforementioned ruse.
Marvel Studios will surely give that “real” Mandarin – the inhumanly skilled Chinese martial artist with ten alien rings of power – his time in the spotlight in Phase Four. It would be a fitting way to end Tony Stark’s arc in the MCU.
Now let’s look at a villain for one of the most exciting newcomers to the MCU.
