Commander Shepard is the main player character of the Mass Effect video games. The character of Shepard is determined by the player, allowing players to decide on the character's gender, appearance, partial history and abilities. Throughout the series, Shepard is on a mission to defend the galaxy against the Reapers: sentient machines that dwell beyond the Milky Way and come every 50,000 years to destroy and harvest advanced organic species. In each game, the Commander must gather a crew and resources, investigate alien worlds and make important decisions that will determine how the story progresses.
In Mass Effect 2, Shepard dies when the SSV Normandy is attacked by the Collectors, a slave race of the Reapers. Shepard's body is found by the human-supremacist group Cerberus, who spend the next two years trying to rebuild the commander with state-of-the-art cybernetics. The Lazarus Project is successful and Shepard is reborn as a cyborg, but all of the commander's cybernetics are internal and still appears entirely biological on the outside.