Vanitas is a slender, androgynous young man of average height with pale skin, large expressive eyes, a round face, and a small chin. His striking blue eyes often compared to the vivid color of copper sulfate are one of his most identifiable traits. His upper left canine is slightly pronounced, giving the illusion of fangs when he smiles, though they are less prominent than those of true vampires.

His hair is long, black, and unevenly cut, with bangs falling into the center of his face. The left side is trimmed to a single length, while the right side has two distinct layers. Although he occasionally appears to wear a ponytail, his hair is usually loose, with the sides cut shorter than the center. A notable cowlick juts out from the right side of his head. Both ears are pierced; his right ear holds a simple stud, while his left ear features a silver (gold in the anime) hourglass-shaped earring inherited from Luna, along with two rings through the helix.

Vanitas typically wears a white shirt with black pants, a dark blue striped vest, a large blue bow tie, and an oversized black coat. His accessories include a long ribbon tied into a bow as a belt, short boots with white spats, and black gloves tipped with claw-like metal at the fingertips. His long coat, fastened with a single button, features a wide collar and balloon-shaped hem, often joked to “float by some mysterious power.” The wide sleeves are inspired by those of a furisode kimono. Attached to his belt are the Book of Vanitas, two knives, and two tool cases. His distinct ensemble is humorously referred to as “the outfit nobody understands.”

In his childhood, Vanitas looked largely the same, though his hair was less neatly cut and his build was more delicate due to his small stature, despite undergoing rigorous chasseur training. Before being Marked by Vanitas of the Blue Moon, his eyes were a noticeably darker shade of blue.

Vanitas presents himself as someone who rarely takes anything seriously, often wearing a playful grin and carrying a mischievous air. He tends to act impulsively, and many of his plans are reckless in nature. He takes great amusement in Noé’s unusual reactions and is unafraid to behave in an openly flirtatious manner, particularly toward Jeanne.

Despite this outward playfulness, Vanitas is capable of seriousness and even flashes of anger when circumstances demand it. Beneath his lighthearted facade lies a deeply damaged individual who harbors resentment toward both humans and vampires, though his greatest loathing is reserved for himself. He dislikes being emotionally vulnerable and avoids sleeping in the presence of anyone he does not trust. Vanitas also has a fondness for high places, frequently spending time on rooftops.

Vanitas was born to a human father and mother, though his mother died during childbirth. Raised solely by his father, the two traveled with a troupe of wandering performers. Vanitas’s relationship with his father was distant, and tragedy struck when their group was attacked by vampires. His father died protecting him during the assault.

After his father’s death, Vanitas was taken in by the Church and began training as a Chasseur. At the time, he harbored a deep hatred for vampires and eagerly anticipated joining the Chasseurs’ mission to eradicate them. During training, he caught the attention of Doctor Moreau, a sadistic researcher. Moreau kidnapped him, designated him as “Number 69,” and staged his death by leaving behind the body of another child with a similar build.

In Moreau’s laboratory, Vanitas witnessed the cruel experimentation on countless vampires. These experiences convinced him that both humans and vampires were equally corrupt. Although capable of escaping, he remained, fearing that Moreau would simply abduct another child in his place.

When Moreau kidnapped a boy named Mikhail (“Number 71”), Vanitas was ordered to care for him. The two formed a close bond, especially after Vanitas volunteered to take Mikhail’s place in a deadly experiment, saving the boy’s life. Moreau, pleased by his willingness, decided to inject both boys with the blood of the Vampire of the Blue Moon in an attempt to turn them into pseudo-Kin and unlock the Book of Vanitas. Before the experiment could reach its lethal conclusion, the Vampire of the Blue Moon arrived, retrieved the Books, and destroyed the laboratory.

The vampire, who would later accept the name “Luna” from Vanitas, offered to take the boys with them. Despite initial hostility, Vanitas gradually accepted Luna as a surrogate parent, traveling with them and Mikhail. Luna taught them about astermite, Malnomen, and the Books of Vanitas, eventually entrusting one Book to Vanitas and the other to Mikhail.

When Mikhail began showing signs of deterioration from the experiments, Luna proposed making both boys their true Kin to cure them. Mikhail agreed, but Vanitas refused, preferring to remain human even at the cost of his life. Nevertheless, Luna eventually turned Vanitas into their Kin before dying in his arms. Critically injured during the same incident, Mikhail was presumed dead by Vanitas.

Following Luna’s death, Vanitas vowed to use the Book of Vanitas to heal Curse-Bearing Vampires and took on the role of a self-styled doctor. He later met Dante, a dhampir information broker, and developed a close working relationship with him despite expressing equal disdain for humans, vampires, and dhampirs alike.

At some point, Vanitas was approached by a vampire named Amelia, who feared she had become a Curse-Bearer. He arranged for her to board La Baleine so they could meet in Paris. Realizing time was short, Vanitas sought out Dante and rushed to intercept the vessel, setting the events of the series in motion.

General
As a human, Vanitas is physically weaker than the vampires he often encounters, lacking their supernatural strength, speed, and endurance. Nevertheless, he is fit, agile, and possesses a heightened healing factor as a result of Doctor Moreau’s experiments. To offset his physical disadvantages, Vanitas relies on exceptional intelligence, quick thinking, and resourcefulness in battle. He is adept at analyzing situations on the spot and formulating countermeasures, often using any available resource to gain the upper hand. Vanitas does not shy away from employing deceptive or unconventional tactics, much to the frustration of his allies.

Weapons and Tools
Vanitas wields a pair of knives equipped with wire-rigged hilts, complemented by various concealed implements he keeps on his belt for both combat and subterfuge. He prefers to hide his arsenal to preserve the element of surprise, reinforcing his unpredictable, trickster-like fighting style. His skill in gathering intelligence on opponents allows him to exploit their weaknesses effectively.

Chasseur Training
Vanitas’s combat expertise stems from his time training as a Chasseur, a role dedicated to hunting vampires. His training gave him in-depth knowledge of vampire physiology and tactics, such as targeting their eyes to disrupt their ability to access and rewrite the World Formula. He has applied this knowledge in encounters against both vampires and other Chasseurs. He also possesses access to combat-enhancing drugs used by the Chasseurs, which he reserves for dire, life-or-death confrontations.

The Book of Vanitas
The core of Vanitas’s abilities lies in his mastery of the Book of Vanitas. Unlike the fearsome reputation surrounding the Blue Moon’s curse, Vanitas uses the book primarily for an “Inverse Operation” (逆演算, Gyaku Enzan), a process that interferes with a vampire’s True Name to extract the Malady and cure them of becoming a Malnomen. This technique requires advanced skill, as most wielders of a Book of Vanitas cannot manipulate True Names at such a level. In rare cases, when the Malnomen’s influence is too strong, Vanitas must rely on the afflicted vampire to reject it themselves, sometimes aided by his Mark of Possession.

The Book also serves as a formidable weapon, capable of rewriting the World Formula for offensive and defensive purposes. Vanitas can immobilize vampires temporarily, though powerful individuals may recover quickly. He can also manipulate Astermite—enabling him to control automatons, cause them to malfunction, or detonate them at will.

Medical Knowledge
Beyond combat, Vanitas demonstrates considerable medical skill, likely inherited from his physician father. He is proficient in first aid, treating poisons, and carrying specialized medicines. His non-combat skills include cooking, cleaning, and an extensive knowledge of French history, culture, and language. He also speaks Latin, a skill likely developed through his Church upbringing and medical background.

Noé Archiviste
Vanitas shares a complicated relationship with Noé, marked by equal parts camaraderie and frustration. He often alternates between urging Noé to accompany him and telling him to leave, resulting in frequent arguments. Vanitas is fiercely protective of Noé yet resents it when Noé tries to protect him, despite having initially asked him to act as his shield. While he refuses to admit any affection, Vanitas clearly enjoys Noé’s company and trusts him. The two often display an unspoken emotional understanding; Vanitas is notably able to calm Noé when he is distressed and has repeatedly saved him from visions of the past and from Naenia’s influence.

Vanitas of the Blue Moon (Luna)
On the surface, Vanitas claims to despise Luna and seeks revenge against them, with many of his early memories portraying this hostility. However, deeper moments reveal a more complex bond. While feverish, he admits, “I didn’t really hate you, Lu…,” suggesting lingering affection. Luna acted as a parental figure to both Vanitas and Mikhail, offering guidance and care. Vanitas allowed Luna to embrace him, and their memory often surfaces when he is curing Malnomen.

Dante
Dante serves as Vanitas’s primary information broker, working with him on a contractual basis and charging steep fees. Their interactions are filled with playful insults, Dante calling Vanitas a “quack” and Vanitas retaliating with “Baldy.” Despite constant bickering, they share a genuine mutual respect and care beyond business. Dante was the first dhampir to be treated as an equal by Vanitas, who, in turn, values Dante’s skills even if he downplays their friendship. They have shared meals together, and Dante is familiar with much of Vanitas’s personal life, occasionally teasing him about a potential romantic relationship with Noé.

Jeanne
Initially, Vanitas interacted with Jeanne primarily to provoke her, finding amusement in her reactions to his teasing and flirtation. Over time, however, he began to show a gentler side, particularly during their time in Gévaudan. Expecting rejection when he flirted, Vanitas was unsettled when Jeanne reacted warmly instead. Witnessing her cheerfulness and strength caused him to develop genuine romantic feelings, though he struggled with the belief that she could never love someone like him.

Amelia Ruth
After Vanitas cured her of Malnomen, Amelia became a friendly and grateful acquaintance. Although she offered him a token of thanks, he declined. Amelia respects his boundaries while occasionally teasing him about his softer side. She demonstrates an understanding of his personality, recognizing his indirect ways of apologizing, and shows concern for his relationship with Noé, even keeping track of their disputes and reconciliations.