Wretched Egg

Shiro, also known as the Wretched Egg, is one of the primary antagonists in the manga Deadman Wonderland. She is the source of the Branch of Sin virus, making her responsible for the existence of all Deadmen.

History
Shiro is the artificial daughter of Hagire Rinichiro who was infected with a mysterious virus that gave her abilities which was being researched by Sorae Igarashi, whose son Ganta the girl befriended. However, as years passed, Shiro suffered horrific human experimentation to have virus evolve into the Branch of Sin strain. Though she became the first Deadman, Shiro's ordeal caused her to homicidal alter ego that became known as the Wretched Egg which caused the Great Tokyo Earthquake. Despite being the opposite of Shiro in nearly every way possible, the Wretched Egg shared her other self's affection for Ganta but from different perspectives. Though she can be subdued by a lullaby generated by Deadman Wonderland's Mother Goose mainframe, there are moments when the Wretched Egg assumes control over Shiro's body.

One such event was the slaughter of Ganta's classmates and giving Ganta his Branch of Sin. Later, Ganta ends up being framed for the massacre and sentenced to Deadman Wonderland where he is greeted by Shiro despite his inability to remember her at first. During that time, the Wretched Egg persona surfaced a bit times with Ganta unaware of at the time. Eventually, the Wretched Egg persona integrates back into Shiro once the Mother Goose system's lullaby no longer represses her and reveals to Ganta that her actions against him were so that he, the one she loves, can be the one to end her misery.

Trivia
Her English voice actress Monica Rial also voiced Dante (in Lyra's body), Mystletainn, and Maria.