Carmilla

Carmilla (カーミラ) was the Witch of Lust. She formally debuted in Arc 4 as a supporting character.

Following her death 400 years ago, Echidna collected her soul and brought it to the Sanctuary along with the other Witches. Throughout Arc 4, she and the other Witches helped Subaru accept himself and change his views on Return by Death. After the arc, her soul was transferred into a crystal and she is currently travelling with Omega.

Appearance
Carmilla stood at 160 centimeters tall, making her taller than the likes of Rem but shorter than the likes of Emilia. She had round red downcast eyes and long pale-pink hair that was parted down the middle and tied into loose asymmetrical bunches falling down the front of her shoulders that went all the way to her hips. As a reflection of her personality, the Witch of Lust's physical demeanour more commonly than not conveyed meekness. Her face looked very refined, and, as opposed to being a standout beauty, Carmilla's charm was derived more so from how abnormally adorable she was. Although her physique was well-hidden by her clothing, Carmilla was known to have a shapely figure with surprisingly large breasts.

Carmilla, who was averse to exposing her skin, would often resort to wearing baggy clothes that hid her generous physique. Her ensemble consisted of a dark-red dress that reached down to her ankles and had diamond patterns on the bottom, a pair of light-brown boots, a long snow-white coat with a pink collar that covered her dress and reached slightly lower down than it, and an exceedingly long light-green muffler that trailed along the ground behind Carmilla. Overall, the only parts of the Witch of Lust's body that were exposed were her head and her hands.

Personality
Carmilla had extremely low self-confidence, often having downcast eyes and overall acted very timid. She tended to stutter and question her own words, more often than not ticking other people off by doing so. She spoke in a very polite manner, trying not to cause any disagreements or disapproval. At times, she showed a rather submissive side of her, when dealing with her fellow Witches of Sin, as seen when she had no problem in taking part of Echidna's scheme to lure Subaru into the Castle of Dreams, despite knowing it would end badly for her. Due to her timid personality and low self-confidence, she was frequently seen shying away from stern gazes, often pleading people not to hit her or exercise any form of violence towards her. This behavior likely stems from her past bad experiences with other people.

According to Echidna, Carmilla only cared for herself and held deep grudges if you were to harm or trick her in any way, regardless of whether or not she was wrong.

Despite her title as the Witch of Lust, Carmilla felt no desire to love or be loved due to a traumatic experience she suffered during her life. Using the Authority of Lust, Carmilla could transform into whomever their target desired to see most.

History
A long time ago, Carmilla was a normal girl who was loved by the people in her village and even had a fiancé. However, one day a man of power came to the village and desired her. Angered by the man's actions, the villagers rose up in defiance and fought against him, eventually burning him with his mansion. The cities and villages around theirs began to regard them as dangerous, causing the fighting to spread, and soon their force was toppling countries, all the while claiming that it was for her sake. Carmilla began to be regarded as a heavenly maiden, nevertheless, she didn't desire such a thing, and saw that they were being misled by their own fantasies and manipulated by their ideals. After they had toppled a large country, her fiancé proposed to her at the top of the castle, though she ignored him and left everything behind, despairing that what she had originally wanted no longer existed.

It is said that over 400 years ago, Carmilla burned to death. Like with the other Witches of Sin, Echidna located her soul and collected it, allowing Carmilla to manifest in the castle of dreams, alongside her deceased friends.

Abilities
Authority of Lust (色欲の権能 Shikiyoku no Ken'nō): Carmilla is able to use the Authority of Lust.
 * Faceless Bride (無貌の花嫁 Mukao no Hanayome):Carmilla's Faceless Bride transformation.gif Carmilla can captivate people, making them so absorbed in watching her that they forget how to breathe, lose all sense of awareness to the point they wouldn't notice if someone stabbed them or if they were burning and in the vast majority of cases, their heart stops beating which results in their death without them even being aware of it.
 * She can also cause people to see and hear her as what they want to see and hear, such as when Subaru saw and heard her as Rem.
 * She also seems to be capable of making people "understand feelings" like love, as seen in the Witch's tea Party when she used her Authority of Lust to help Subaru understand Satella's love for him.

Trivia

 * Like the other Witches (with the exception of Satella), Carmilla's namesake matches both an asteroid and a mythological being. 107 Camilla is the name of a large asteroid located in the solar system's asteroid belt. The mythological Camilla was a warrior virgin in Roman mythology.
 * According to the author, Carmilla's birthday is June 19.
 * In the Web Novel, Carmilla was 17 years old at the time of her death.
 * Due to Carmilla's lack of fighting abilities, she had personal guards who protected her. The author also noted these guards were able to resist her Authority to some extent because they had "tough hearts".
 * Very few people actually met Carmilla and got to walk away with their lives, due to her Authority of Lust.
 * If Carmilla and Capella were to fight to the death, it would conclude with Carmilla's victory (barely but surely).
 * In 2014, the author stated that Carmilla was among nine known characters introduced in the story up to that point who had the highest capacity for holding mana. However, he chose to not rank Carmilla or any of the other listed characters in order. It is unknown if the list has changed since then.