It’s no secret that Iron Man (Robert Downey Jr), although a beloved character and the savior of the universe in the Marvel Cinematic Universe, was a deeply flawed character, and through the dark mirror linked to one villain, Marvel showed Tony Stark’s biggest flaw. Iron Man battled a variety of enemies during his time in the MCU, and some of them turned out to have been unintentionally created by him or were somewhat linked to him and his backstory, which added even more layers of complexity to his character.
https://screenrant.com/iron-man-2-secret-stark-dark-mirror-biggest-flaw/