Marie, whose true name is Marguerite Breuil, is a central character in Dies irae. She is a mysterious young woman from 18th-century France who was executed by guillotine, leaving a visible scar on her neck. In the story, she first appears in the dreams of protagonist Ren Fujii after he views a guillotine at a sword exhibition. She forms a contract with Ren, allowing him to unlock his latent powers and become a key figure in the conflict against the Longinus Dreizehn Orden.

Her personality is marked by a paradoxical nature, encapsulated in her phrase, “I shall hate and love you.” She carries a pure, angelic demeanor but is burdened by a cursed past. Her motivations are intertwined with Ren’s journey, as she serves as both a guide and a catalyst for his transformation. She is designated as the Fifth Heaven, a being of considerable power within the series’ metaphysical hierarchy.

Marie’s role in the narrative is that of a primary heroine, deeply tied to Ren’s character development. Her backstory and relationship with Ren are explored in dedicated story routes, where her tragic history and her bond with him are central to the plot. Her most notable ability is the contract she establishes with Ren, which enables him to manifest his own abilities. Additionally, as a heavenly being, she possesses inherent supernatural attributes, though the full scope of her powers is revealed gradually through her story arc.