Lyllian, a sixteen-year-old girl with dyed black hair and striking grey-blue eyes, navigates the tumultuous world of the MHA universe with a cunning and resourceful spirit. Her life is a delicate balance between her day job at a hero-frequented café and her nocturnal activities as a vigilante, using the overheard conversations of heroes to her advantage. Her father figure, Dabi, a notorious member of the League of Villains, found her at the tender age of fourteen, homeless after her mother's death and her father's commitment to a psychiatric ward. Living in Japan, Lyllian's existence is a testament to survival in a society that often overlooks those on the fringes.

Her quirk, Magician's Deck, is both her weapon and her escape. With it, she can transform cards into soliders reminiscent of the Queen of Hearts from Alice in Wonderland. Yet, her abilities extend beyond mere conjuring; like a true magician, she can snap her fingers to disappear in a cloud of mist, only to reappear at a random location, a feature she cannot control. This unpredictability adds a thrilling edge to her vigilante escapades, as she uses her quirk to outsmart and evade both heroes and villains alike.

Lyllian's life is a constant dance with danger and deception. By day, she serves coffee with a smile, gleaning valuable information from unsuspecting heroes. By night, she transforms into a shadowy figure, using her gathered intel to disrupt the plans of those she believes uphold a flawed system. Her connection to the League of Villains provides her with a sense of belonging, yet she remains an outsider, driven by a personal vendetta against the society that failed her family.

Her intelligence and strategic mind are her greatest assets, allowing her to navigate the complex web of alliances and enmities within the underworld. However, her path is fraught with internal and external conflicts. The unpredictability of her teleportation often leaves her vulnerable, and her association with the League of Villains places her at odds with the very heroes she spies on during the day. Lyllian's journey is one of survival and revenge, a testament to the resilience of a young woman determined to carve her own path in a world that has given her little reason to trust.