Elizabeth, often referred to as the Blood Queen, is a central antagonist in the Lawless City arc of the second season. She is a Vampire Progenitor, one of the most ancient and powerful beings of her kind, and is recognized as one of the three monarchs ruling the Lawless City alongside Yukime and Juggernaut. Physically, Elizabeth appears as a beautiful vampire woman with a slender build, very light crimson hair that reaches her knees, and eyes of a matching red color. She has pointed ears, a trait she shares with elves, though her hair typically covers them. Her attire primarily consists of a knee-length dark red dress, which is described as being made of blood that moves hypnotically against her skin, complemented by matching red accessories and an umbrella she uses to shield herself from the sun.

Elizabeth’s personality is remarkably different from what one might expect from a progenitor vampire. Unlike others of her kind who use their power for survival or evil, Elizabeth is known to be benevolent and kind-hearted. Her deepest desire has always been to prove that peaceful coexistence between vampires and humans is possible. She once dreamed of building a haven, a land where both races could live together in harmony. This gentle nature, however, stands in tragic contrast to her biological needs. It is very difficult for her to fight off the primal urge to feed on human blood, a struggle that defines much of her history. When she first woke from a long slumber, she suffered from a form of low blood pressure, making her a famously slow riser. Despite her immense power, she is not aggressive by nature and has historically refused to take human lives excessively, hunting only the bare minimum required for her survival.

Elizabeth’s role in the story is rooted in a tragic past. Long before the events of the series, she successfully established a peaceful community called Haven, where humans and vampires lived together under her protection. This peace was shattered by her subordinate, Crimson, who feared she had grown weak. During the appearance of a Red Moon, a celestial event that greatly amplifies the power and frenzy of vampires, Crimson treacherously fed the people of Haven to her. Consumed by an uncontrollable bloodlust under the crimson moon, Elizabeth went on a devastating rampage, annihilating several countries in just three days before finally being stopped and falling into a state of suspended animation. In the present day, Crimson orchestrates a plot to resurrect her, using countless human sacrifices in the Crimson Tower to awaken her once more, this time intending to use her as an uncontrollable weapon. For most of the arc, she exists not as a scheming villain but as a force of nature, awakened into a frenzied state, attacking everyone instinctively as her power rapidly escalates.

Key relationships define her narrative, with the most significant being her bond with Mary, a vampire hunter. In the past, Mary was Elizabeth's close companion and servant. After Elizabeth lost control, she begged Mary to ensure she could never revive and cause more tragedy, a promise Mary kept by guarding her remains for centuries. Their relationship is deeply emotional, with Mary desperately trying to reach the Elizabeth she once knew, pleading for her to stop her rampage. Another crucial relationship is her antagonistic connection to Claire Kagenou and, by extension, Shadow. It is Claire who is grievously wounded by Elizabeth, an act that eventually draws out the Witch of Calamity, Aurora, from within Claire’s body to fight the Blood Queen. This conflict leads to her final confrontation with Shadow, who recognizes that she is not acting out of malice but is a victim of circumstance and a cursed nature.

Throughout the climax of the arc, Elizabeth experiences a significant and unique form of development not through conversation, but through a direct action by the protagonist. As she battles Shadow, her power and bloodlust reach their peak under the Red Moon. Instead of destroying her with a massive attack, Shadow uses a technique called Recovery Atomic. This ability does not harm her but instead completely purifies the vampiric frenzy and corruption from her body, effectively curing the madness inflicted upon her by Crimson’s betrayal. Freed from her uncontrollable instincts, Elizabeth returns to her true, peaceful self. Her development concludes with her decision to relinquish her position as monarch of the Lawless City and set out on a new journey with Mary, searching for a true "place of rest" and finally seeking the peace she always desired.

Elizabeth possesses a vast and terrifying array of abilities befitting a Vampire Progenitor. Her primary and most versatile power is blood manipulation, which allows her to control her own blood and the blood of others for offense and defense. She can launch powerful blood projectiles that cover entire areas, shape her blood into solid weapons, and even create clones of herself from blood. By absorbing the blood of her opponents, she can rapidly heal herself and grow even stronger, a power that becomes nearly limitless under the influence of the Red Moon. Her regeneration is among the strongest of her kind; as long as her heart remains intact, she can reconstruct her entire body, even from a puddle of blood. Additionally, she can transform her body into an intangible mist, allowing her to evade almost any attack. Elizabeth's power is so immense that when fully awakened under the Red Moon, she was able to destroy three countries in as many days. Despite this godlike power, she retains the classic vampiric weaknesses; prolonged exposure to sunlight burns her skin, and abstaining from human blood weakens her significantly.