In Overwatch, D.Va (real name Hana Song) is a former professional gamer from South Korea. After the Omnic crisis, she was drafted into the military, to pilot MEKA mech suits in defense of her nation. She takes this on with a fearless and upbeat attitude and like most gamers, indulges in junk food in her downtime.
Tony Stark is Iron Man, a billionaire playboy and ingenious engineer who, after being kidnapped, builds a powered suit of armor to escape captivity. As a free man, he continues to build new models of the suit, wearing them while playing the hero.