An out of work actor hired to play a terrorist on television, who was the only person involved not in on it.
Trevor Slattery is an English actor, washed up and addicted, who is hired by Aldrich Killian and Advanced Idea Mechanics to play a terrorist called the Mandarin in a series of broadcasts. The persona is stitched together from modern terrorists and a supposedly legendary Chinese title, and the videos are cover for A.I.M.’s explosive Extremis experiments. Slattery does not know any of that. He lives surrounded by the wealth and drugs A.I.M. provides until Tony Stark finds him, and is arrested pleased with the publicity.
Ben Kingsley plays him, and the reveal that Kingsley was playing Slattery rather than the Mandarin was the most divisive thing in Iron Man 3. Comic readers objected to what it did to a major villain. Others defended it as commentary, and for avoiding the racist caricature the comics’ Mandarin had been. The character then outlasted the argument, which is the strange part: he has appeared in four titles, which is three more than the film’s actual villain managed.
Minor spoiler
In the short All Hail the King he is in Seagate Prison, with a personal “butler” and a fan club among the inmates, until Jackson Norriss, a Ten Rings member posing as a documentary filmmaker, breaks him out with the news that the real Mandarin is angry about the use of his name.
Shang-Chi and the Legend of the Ten Rings picks him up years later. The Ten Rings sentenced him to death; their leader Xu Wenwu instead kept him as a court jester after Slattery entertained him with Shakespeare monologues. Sober and somewhat refined, he has befriended a captured hundun he calls Morris. He escapes the compound with Wenwu’s children Shang-Chi and Xialing and their friend Katy, travels with them to Morris’s home at Ta Lo, and helps defend the village against the Ten Rings and then the Dweller-in-Darkness. He and Morris are among the mourners at the funeral afterwards.
Wonder Man is set two years on. He returns to Hollywood to act again, is detained by the FBI and the Department of Damage Control, and takes a deal to inform on Simon Williams, an aspiring actor the department claims is dangerous because of powers he hides. Over months of auditions, both of them going for the remake of the in-universe film Wonder Man, he mentors Williams and becomes his friend, and Williams eventually confides his secret. When Williams finds out what Slattery has been doing he destroys a soundstage in a rage. With the department closing in, a remorseful Slattery puts the Mandarin persona back on and broadcasts a claim of responsibility, and is sent to a supermax prison for it. The film is a success without him. Williams, lonely, breaks him out, and the two fly off together.