Meg Masters is a frequent antagonist in Supernatural.Although her name was never revealed in Supernatural, she is better known as Meg after owning a human girl, she is also the daughter of Azazel, she is secundary antagonist in season 1 of the series, a minor antagonist in season 2 and 5 and an antiheroine for the remainder of the season before his death at Crowley's hands.

Cassandra Masters is the daughter of Castiel and Meg Masters and the only known Nephalem to exist, which is a hybrid between a union of an angel and demon, even being part human due of Castiel and Meg's human vessels.. Cassandra acts as one of the leading main characters with Sam and Dean. Throughout the story, she serves as a protagonist and later rules over Heaven.