Kevin Feige has teased that Marvel do have plans to use the 'real' Mandarin and the Ten Rings in the MCU's future.
The Marvel chief was taking part in a Reddit AMA (or, technically, AMAA) when one user asked the question about potential plans for the group or the real version of the Mandarin, teased in One-Shot 'All Hail The King', to which Feige simply replied: "Yes."
He's obviously not giving a lot away at this stage, but it's also a pretty direct confirmation that the villains will be coming back at some point. The Mandarin, of course, served as the antagonist of Iron Man 3, before a very Shane Black twist revealed that he was instead a British actor by the name of Trevor Slattery (played by Ben Kingsley) hired to play the role, with scientist Aldrich Killian the real villain of the movie.
However, the All Hail The King One-Shot teased that the actual Mandarin did indeed exist, he just hadn't revealed himself yet, and that the terrorist organisation Ten Rings were still in operation. Given the divisive nature of the Mandarin twist, and the fact he and the Ten Rings are big villains who haven't been fully explored by the movies, there's long been a desire to see them used more in the MCU.
So how could they appear?
Given the Ten Rings featured in Ant-Man with an interest in Pym Tech, there's potential they could return in Ant-Man 3/Ant-Man and the Wasp 2 as the main villains, assuming that film happens at some point. The other possibility is that they're introduced in Shang-Chi, which is very much in active development. Given the issues around the Mandarin being a racist stereotype was why Black didn't include him in Iron Man 3, the character would need some updating, but with the right filmmakers on board (which Marvel have for that film) then there should be a way of giving him an update that does work in the present day.
Do you want to see the Mandarin and Ten Rings back in the MCU? Let us know down in the comments.