Marie hails from an area outside of the Canopy Kingdom known as No-Man's Land, a wasteland that used to be a country but fell during the war with the Canopy Kingdom. Along with her friend Patricia (who would later become the Anti-Skullgirl weapon Peacock), Marie was orphaned during the war and forced into slavery by a group funded by the Medici Mafia. Originally the boss of Skullgirls, Marie first becomes playable in Skullgirls: 2nd Encore's Season 1 Pass in 2023.

Seven years after the war, Marie obtained the Skull Heart through unknown means. She used it to punish the slavers who had tormented her and Patricia, but transformed into the Skullgirl in the process. However, her strong will allowed her to resist the influence of the Skull Heart and continue her quest of vengeance - having disposed of the ones who enslaved her and Patricia, she turned her attention towards their sponsors: the Medici Mafia.

After arriving in New Meridian, Marie set up base in the catacombs of the local cathedral. She joined forces with the mysterious Double, although the exact nature of their meeting is still unknown. Marie also came into conflict with "Last Hope", an elite squad of Anti-Skullgirl Lab operatives, and wiped them out. The sole survivor, Valentine, was coerced into joining the Skullgirl as her second elite minion.

Some time later, Marie discovered that a number of people around the Canopy Kingdom were seeking her out, each for their own reasons. She waited in the catacombs beneath the cathedral for anyone bold enough to challenge her, but the true version of events remains unknown.