D.Va is known as Hana Song (her real name) is a 19 year old professional gamer (formerly). She is also the Mech Pilot in Overwatch. Her role on Overwatch is Tank hero in Heroes selection on the game. Her health points for Pilot is 150 and Mech is 400. It is like you have two lives. Not to mention that her armor is 200 for her Mech.
Eject!: Even though the icon is on only in the Hero Details but D.Va ejects out of Mech when the Mech health went down to zero.