Catherine Morningstar was the third child born to Lucifer and Lilith, the rulers of Hell, two minutes after her older sister, Charlie Morningstar, and a few hundred years after her brother, Damien, who was taken by Heaven shortly after his birth. Catherine, more commonly known as Cathy, grew up rather sheltered by her parents. As the daughter of the king and queen of hell, Charlie grew up around the Deadly Sins as well as the Von Elderitch family.
Growing up, Catherine would become close to some of the imp servants that worked in the Morningstar palace. While these imps were treated well, Cathy heard about how imps outside of the royal family were treated. These stories stayed with Cathy and were the driving point towards her desire to improve the lives of the hellborn.