Sinthea Shmidt, better known as Sin, Red Skull, and Mother Superior, in an antagonist in Marvel Comics. She is the daughter of the main Red Skull. She was created by J.M. DeMatteis and Ron Frenz, and first appeared in Captain America # 290 in February 1984. Seeking an heir, the Red Skull fathered a daughter with a washerwoman. The woman died in childbirth, and the Red Skull almost killed the child, angry that it was a girl. One of his followers, Susan Scarbo, convinced him not to, telling…