This story starts with a solid battle against Crimson Dynamo where Iron Man kills him to subdue him.

And then brings him back to life using his repulsors as a defribulator. Captain America is concerned by this, and as readers it does seem out of character.

And it is.

The son of Ho Yinsen, the man who saved Tony Stark’s life in (Vietnam/Afghanistan) has returned and is mind-controlling Tony Stark via Tony’s new Extremis armor. He proceeds to use Tony as a weapon to kill all the people responsible for his father’s murder.  Thus, Iron Man becomes an assassin and all the heroes have to hunt him while he tries to clear his own name. 

He becomes increasingly bloodthirsty along the way (but it’s because he’s being controlled by Yinsen Jr.).

He even spends a bit of time in Leavenworth before he escapes.

The big finale has Nick Fury putting a bullet in Yinsen’s son’s head.

This launches a mass attack of five of Iron Man’s suits against just about everyone…

This is the big “Execute Program” in the title of the arc. 

Tony “kills himself” to stop the attack, but then is able to restart his heart a few minutes later.  What Tony learns from all this is that he should support the Superhuman Registration Act because even a hero as awesome as he is can be manipulated into becoming a bad guy.

Oh, and he’s blonde now.