Kaien Cross

Headmaster Kaien Cross (黒主理事長, Kurosu Kaien Rijicho) is both Headmaster of Cross Academy, and current head of the Vampire Hunters Association. He is also known as the strongest vampire hunter in history, and is quite the legend. He is the guardian of Zero Kiryu and adoptive father of Yuki Cross, the heroine of the story.

Character concept
In the first and second arcs, Kaien's role in the story is largely observant, and he takes little action until the hunter's association attacks the Night Class at the end of the second arc. After this point in the series, Kaien takes on a more direct role in the action.

Name
Cross or Kurosu, means "black master." Kaien is a combination of kai, meaning "ashes", and en, meaning "village gate." The kanji for en is also used for Enma the ruler of the Underworld in Buddhist mythology. Kaien often asks Yuki to refer to him as "father" when she calls him "Headmaster".

Appearance
Kaien has long straw coloured hair and usually pulls it back into a ponytail. Though he is over 200 years old, he looks to be in his mid twenties. Kaien enjoys wearing very odd clothing and can be spotted with oversized lion feet slippers and large colourful hats. Kaien is one of the few characters that wears spectacles, though he removes them in times of action.

Personality
Kaien sports a cheerful personality, yet can be serious at the same time. It can be said that he has a few odd personality quirks, such as his propensity to launch into tearful dramatics over the idea of being a poor parent to Yuki. Additionally, he enjoys ribbing his adopted children, particularly Zero, often mocking him about being a vampire as he refuses to consider Kaien and Yuki family, a fact which Kaien jokingly claims breaks his heart. Kaien also enjoys cooking very strange food and making Yuki and Zero eat it.

Kaien can also appear thoughtless, frequently overriding and ignoring Zero's distaste for vampires. He often tells only half truths to protect Zero and Yuki, and kept his knowledge of Yuki's past secret from both her and Zero. He is however quite proud, and very protective, of both his children.

Background
Kaien has not always been so happy go-lucky. At his prime as a Vampire Hunter, Kaien Cross was known as the "Vampire without Fangs" due to his strength and skill as a Vampire Hunter, and also the fact that he was born with an abnormally high amount of vampire genetic material compared to other Vampire Hunters. Thanks to his vampire DNA, Kaien is over 200 years old and no longer seems to age.

Kaien is friends with pureblood vampire, Isaya Shouto, and used to intentionally pick fights with him. After befrending Juri and Haruka Kuran, Kaien took on Juri's dream of establishing a school for vampires and humans, and retired as a Vampire Hunter in order to establish Cross Academy 16 years prior to the story's beginning. Following the deaths of Juri and Haruka, Kaien took in their hidden daughter, Yuki, after Kaname Kuran brought her to him for safekeeping. Thus Kaien became Yuki's very doting and slightly odd father, much to Yuki's annoyance. Kaien also took in Zero Kiryu several years later, after the deaths of Zero's parents. As he did with Yuki, Kaien also wished to adopt Zero, but Zero refused.

Shortly after Zero's arrival, Kaien, with Kaname's assistance, is finally able to establish the Night Class to promote understanding between humans and vampires. Due to the vampire presence at the school, Zero initially refuses to attend high school and is left behind a year, but Kaien is later able to convince him to attend the following year in order to prevent Yuki from being alone in the duties of being a guardian.

Juri Kuran
Kaien and Juri met as enemies when Kaien tried to kill her and they eventually became good friends. There is some suggestion that Kaien may have held romantic feelings for her. What is clear, however, is that Kaien held both Juri and Haruka Kuran in high regard during the years of their friendship.

Powers
Kaien is a very strong hunter, known as the best until he retired. Kaien is unusual amongst the vampire hunters, having stopped aging at 25 years old, they have been studying his DNA, which he is said to possess extremely high amounts of vampire DNA that stopped his aging and causes Zero to confuse him with that of a vampire's aura. Like all vampire hunters, Kaien is able to wield anti-vampire weapons and carries a sword hidden in a cane and he has an acute smell that senses vampires.