||Spoilers! - Emeralda's body is actually a nanomachine colony that hosts a human soul. Thus, she is reffered to as the "Soul Vessel". Besides, she bears the DNA information of her "parents", Kim Kasim (Abel/Fei incarnation) and his wife's, Elehaym, cells. The Zeboim civilisation was in sentenced to perish, since the birth rates and human infertility increased due to enviromental pollution and nuclear wars. Kim Kasim, a scientist, hoped that nanomachine technology could solve the infertility problems and thus created Emeralda as his daughter and humanity's "Guardian Angel". 4000 years later the actual events of Xenogears take place and the Zeboim ruins are discovered. Emeralda's reactor is reactivated by the player's party and she awakes, but is abducted by Solaris Special Forces. Some events later, she encounters the party as an enemy, but is defeated and joins. Near the end of the game, she can visit the "Lighthouse", where she remembers her past and thus changes into a 16-year old version of herself.