German-born twin teenage sisters and the adoptive daughters of Gene. Both are gifted with extraordinary psychic abilities , implied to be as a result of exposure to nuclear fallout during the Kyshtym disaster, though Ursula is the stronger of the two. Ursula is a member of FOX, while Elisa is the medic who watches over Null.However, Elisa is later revealed to suffer from dissociative identity disorder, and Ursula is actually her alternate personality.
During the San Hieronymo Incident, Ursula (the more powerful of the two) was a member of the FOX unit and a loyal follower of Gene, while Elisa became a researcher who watched over Null. Later, Elisa helped out Big Boss, until it was revealed that Elisa suffers from dissociative identity disorder, and that Ursula is not her twin sister, but an alternate personality produced by the experiments performed one them: the bulk of Elisa's powers were transferred to Ursula.
As Ursula, she later inhabited Metal Gear RAXA and fought Big Boss, using her powerful psychokinesis to allow the Metal Gear to move and act in a natural manner, as if it wasn't a machine at all. She survived the battle and turned against Gene when he threatened to launch a nuclear missile, but Gene overpowered her and stabbed her. While Big Boss cradled her in his arms, Elisa, in her dying words, told Big Boss his future; she had predicted that Big Boss will build his own Metal Gear after destroying RAXA, the occurrence of the Les Enfants Terribles project, and ultimately revealed that his son will bring the world to ruin and another son will save the world.
