In Metal Gear Solid 2: Sons of Liberty, Raiden’s real name is Jack. He is introduced as a newly assigned FOXHOUND operative during the Big Shell chapter of the game.
Raiden’s background is gradually revealed through Codec conversations and story scenes. Before joining the military, he had been involved in the Liberian Civil War and was known as the “White Devil.” The game deliberately withholds much of this history at first, making his identity and past part of the narrative’s larger revelations.
Jack is not the same person as Solid Snake, whose legendary reputation shapes Raiden’s mission. The name also connects Raiden to Rose, who calls him Jack during their personal conversations. Later games expand his history and transform him into a cybernetic combatant, but Metal Gear Solid 2 presents him primarily as a young operative learning under extraordinary circumstances.