Back to where it all began, Yinsen played an instrumental role in helping Tony Stark transform from the egocentric narcissist he was into a selfless hero. Okay, maybe the self-proclaimed genius/billionaire/playboy/philanthropist didnt change completely, but the time he spent in a cave with his fellow captive was definitely a step in the right direction. Yinsen helped Tony build the Iron Man prototype and then bought him precious time to make his escape before making the wrenching revelation that the family hed fondly spoken of were long gone.