While on his Isle of Exiles stronghold, the Red Skull (Johann Shmidt)
choose a peasant washerwomen reminiscent of his mother to bear his heir. The woman died giving birth to a daughter. Desiring to have a son, the furious Skull spat in the dead woman's face, then took the newborn to cast her into the sea. Convinced by his underling Susan Scarbo
to spare the child, the Skull ordered Scarbo to be her "night mother" and raise her in misery, anger and hatred at the Skull-House, an old Catholic monastery, only seeing her himself five minutes a week. The young Sinthea Shmidt became a beast of a girl, Susan Scarbo's prize pupil. When Sinthea was still a young girl, the Skull learned he was dying. Needing an instant heir, he used his Deus Machina to artificially age her into adulthood, mentally indoctrinated her, and empowered her as Mother Superior. The Skull also aged and empowered four orphan girls whom he had taught to revere Sinthea as a goddess, creating the Sisters of Sin
:Sisters Agony (aka pain), Death, Dream, and Pleasure.