Sin, the daughter of The Red Skull, is rumored to be making her Marvel Cinematic Universe debut. The character, who first appeared during J.M. DeMatteis and Ron Frenz's time on Captain America in the 1980s, is named Sinthia Schmidt, and has a healthy disdain for her father, but doesn't use that as an excuse to be a hero, but rather to try and one-up him on the villain scale as an ally of Crossbones and HYDRA. The idea that she might pop up in the MCU makes some sense, given that The Falcon and the Winter Soldier established our next-generation Captain America.