Madison Mazos is the head of the “Infernal Family” criminal gang, who got into Valkyria right after X-Day in 2175. In the first years of her stay on Valkyria, she was able to intensify her criminal activities in Sector Zero. She was engaged in the illegal distribution of a synthetic version of DSL-38, which in low-quality, but high doses cause strong euphoria in humans and cyborgs, and also temporarily blunts the Aethernagonia disease, which cyborgs suffer from unsuccessful body implant transplants. This cheap and low-quality version of the substance also causes strong dependence and gradual erasure of personality in humans and cyborgs. Madison gives out a dose to the members of her gang for certain merits. Unlike many, she does not use cyber implants.

She was born with her brother Charles into the family of military chemist Ridley Masos, who instilled in her an interest in studying various chemicals and how they affect the human brain. From the very beginning, she was severely deprived of parental care and attention and often showed signs of aggression. At the age of 25, she was sent to a women's colony near San Quentin for the murder of a man who tried to molest her. At the same time, she learns that her father dies in a plane crash for unknown reasons, which further affects her character. While in prison, she begins to understand more how the principles of the criminal world work and shows a special interest in this. Two years later, she makes an escape, which is organized by her brother along with the "Doomsday Angels". While at large, she and Charles go to the vast expanses of Arizona, where they create their own little gang, the «Infernal Family". For four years, the gang successfully engaged in robberies and night raids on trade caravans.

As soon as she found out about the beginning of X-Day, she, Charles, and several other gang members go to Valkyria in Sector Zero to settle there forever. 9 years later, her gang is joined by albino brothers who, with the help of hacker attacks on the computers of Deborah Hadid's laboratory, steal the genetic data of the medicinal substance DSL-38 and develop its synthetic version, acting as a drug that causes severe psychological dependence.