Hinami Karnstein

Hinami Karnstein is a succubus and Mina Karnstein's Guardian after the death of her adoptive parents. She is the daughter of Lucia and little sister of Lilim, it is later revealed that Hinami is also the daughter of Marius, thus making her the niece of Maria, the younger half-sister of Sataniel and Mina, and the cousin of Arthur and Le Fay Pendragon.

Appearance
Hinami is a petite beautiful girl with long white hair and purple eyes in her human form most of the time. She is seen dressed in a black dress that has white frills most of the time and what seemed to be like a functional keyhole on her collar, where her magical key is meant to be inserted in, black leggings, and boots that have a purple hearts on them.

In her succubus form, she has slit purple eyes and small black horns on her head, dressed in a black leather revealing outfit, white leggings with light pink horizontal stripes, and black boots, as well as four small black wings located near her waist and upper back.

When using her Magic Key, Hinami takes on the form of a full-grown older woman with a curvaceous figure, large breasts surpassing Mina and Ariel, and was taller and slender compared to Tomoe, as well as thick black gauntlets and having multiple tails.

In Volume 24, whenever using her Revere Magic Key, instead of an adult, Hinami still maintains her usual height and revealing black outfit, with long thicker black horns, thicker black more demonic gauntlets, more tails, and a more elaborate cross-shaped keyhole.

Personality
Hinami is rather childish and likes teasing people no matter how serious the situation. She prides herself on trying to make light of most situations to counter the seriousness of Arthur and the rest of the harem. She's often referred to as being the "problematic" member of the family due to how brutally honest she is about her feelings and desires.

Being a succubus, Hinami naturally feeds off of the lewd situations. In the first half of the series, she's primarily scheming and watching Arthur engage in lewd acts with the rest of the harem in order to deepen their bonds. However, in the second half of the series, she becomes an active participant in the lewd situations, and even discovers that she's a bit of a prude and a masochist when it comes to others watching her engage in lewd acts with Arthur.

Outside of being a prankster and tease, Hinami has a vulnerable side. As a child, she was repeatedly told that her mother's appearance was her fault. Hinami then internalized that and spends the majority of the series blaming herself for her mother's condition. She also has moments, quite a few moments, where she's brought to tears and questions her worth and role in Pendragon Residence.

She's in love with Arthur, as with the other members of the harem. However, unlike the other girls, Hinami often pushes her feelings down, and rationalizes it by saying "she's supporting Arthur deepening his bonds with the other girls". She has some moments though where she puts her feelings first and rewards herself with quality time with Arthur.

Hinami also values the other girls in the harem and is good friends with them, as well as the of the tenants of the Pendragon household. She's good at keeping some of the more embarrassing secrets of some of the girls and does everything she can to help when they might be in a pinch.

Past
Hinami was born the illegitimate daughter of the then current Vampyre King Marius Karnstein and a succubus of great renown Lucia. In the same way that Marius gave the majority of his power to his son Sataniel and first Daughter Mina, Lucia also decided to gift the majority of her power to Hinami, which as a side effect has reduced Lucia to a weakened and younger looking form.

Six month's prior to the series start Hinami and clones of the wolfs, Sköll and Hati, were sent to rescue Mina whose adoptive family was under attack by the Greek God of War, Ares, then her and Mina narrowly escaped thanks to Skoll and Hati using their full power to hold off Ares. Since then, the two of them were on the run until they were found by Jin Pendragon and Bann Du Lac, who tricked Jin into trying to brainwash him, into taking them in under the pretex that he was going to marry their mother.

Succubus/Vampyre/Devil Power
Hinami is both the daughter of the strongest succubus and Vampyre Lord, as such she has remarkable abilities for her age. She is also noted to be a power-type classed as a Hard Striker, focusing on strength and close-combat able to perform powerful strikes, which is able to outclass that of Arthur at first. As a succubus, she has all the abilities as one letting her look into and control the dreams of others, as well as being able to grow stronger through using both the sexual desires and actions of others as shown as she could fight against Percevall who was sent to eliminate Mina Karnstein. Through the use of the Eye of Azathoth and her Magic Key, she has enough strength to be classed as an SS-Rank Demon and could have fought against Zephon. Near the end of Volume 20, Hinami is noted to have potential to rival that of her father and older brother. Magic Expert: Though Hinami is classed as a power-type, she is well-versed in a number of magic and techniques most of which is related to her heritage as a succubus. She is also the one who taught Mina about how to use her magical abilities soon after the death of her adoptive parents. Hinami can also distort and erase the memories of others. Master-Servant Contract (Servant): Hinami formed a master-servant pact with Arthur in Volume 20 in order to transfer her Wood Element, which soon developed into a Master-Servant Vow.
 * Superhuman Strength: Despite her small size, Hinami is a strong succubus. Her skills can't be compared to Arthur considering he easily overpowers her, even after being rusty due to his exile from the Village.
 * Succubus Powers: Being the daughter of a succubus, Hinami has all the common abilities of one, letting her look into and control the dreams of others, able to grow stronger through using both the sexual desires and actions of others. In Volume 21, she is able to use those same sexual acts to restore the life force lost from using her Reverse Magic Key.
 * Baptism: Hinami can perform a baptism on others causing the same aphrodisiac effect of the master-servant contract.
 * Gravity Steuerung: After she lost against Nico in Volume 7, Hinami decided to become much stronger and soon started to train with Arthur. It was then that she discovered that she can manipulation gravity like Mina, Satanael, Arthur and Le Fay (who she is later revealed to be related to both). Though unlike them, she doesn't have particular control over it and it puts a strain on her due to not understanding how it worked at first.
 * Gravity wave: During her battle against Dante and Legion in Volume 21, Hinami is able to channel the gravitional force into her fists to create a crimson shockwave to help her deal with Legion.
 * Master-Servant Contract: Through using the full moon (when in the human world), Hinami is able to create master-servant contracts for others using either the powers of the contractee. However, for Arthur, the others and later Lancelot, she instead used her succubus nature, which results in an aphrodisiac curse, which is relative to the individual who cast it. As such, it had caused a light curse throughout Arthur's "conquest" of the other girls. However, after she tied the Master-Servant Vow with Arthur, the aphrodisiac effect of the contracts utilizing her magic has surpassed her mother.

Necronomicon
Necronomicon (ネクロノミコン, Nekuronomikon) is a book ,which is said to look like it was made from human skin and be heard moaning in despair and pain, containing ancient information about the old ones, Ancient deities born before even time itself, and how to contact them from any realm and even draw power from them. What makes it even more puzzling than other spellbooks is that its origins and creator are unknown.

Despite the original one being sealed away and all other forms of it being destroyed once found around the world, Hinami was given an nigh-exact copy of the original one by Zephon. With it, Hinami is able to open portals and extract knowledge and powers directly from the Realm of the Old Ones and Valkyrie Council, enabling her to perform several feats such as an accelerated regeneration, the purest and darkest forms of magic and spells and even be able to summon mini-Old Ones, demonic spirits and familiars to fight her foes.

Eye of Azathoth (アザトースの眼, Azatōsu no Me):

Magic Key: Hinami's trump card, which lets her release her limiters increasing her power to a greater extent and it causes her to grow into an adult woman.
 * Reverse Magic Key: Once Arthur, Le Fay and Hinami learned the truth about her birth and unlock her true power. In her battle against Kouryuu in Volume 21, instead of turning into an adult, she had remained in her usual size with long thicker black horns, thicker black demonic gauntlets, three long black tails, and a more elaborate cross-shaped keyhole. In this form, Hinami attained immense power and speed, using this power is that it depletes Hinami's life force.

Trivia

 * Plays the trial version and reads the reviews of eroge games in order to help Arthur with the harem.
 * Her first sexual intercourse was vaginal
 * She is the main cook in the Pendragon house alongside Elaine Du Lac and Annabelle Van Helsing.
 * In the short story, "Go West to Flower Fruit", it's revealed that Hinami has Coulrophobia (the fear of clowns).
 * She is very fond of animals, especially cats.