Iron Man 3: There's this guy named the Mandarin who is bombing places and releasing videos calling out people (the president/Iron Man). Eventually Iron Man finds the Mandarin only to find out it's just some actor named Trevor Slattery. He was hired by another villain who Iron Man defeated. Trevor is thrown in jail
All Hail The King: Someone goes to the jail to capture Trevor, they say someone didn't like using the Mandarin's name and using his organization "The Ten Rings" in their videos
That's all we know going into shang chi. It's really not that big
Nice, thank you for the summary, hope your day is well and you succeed in your endeavors :)
