Vampire

Vampires (吸血鬼 or ヴァンパイア, Banpaia) are the supernatural creatures of the Vampire Knight universe. As in traditional folklore, they are sensitive to the sun and are active during the night; however, in reality, sunlight only hurts their eyes and does not actually cause them any physical damage.

When killed, vampires will turn into sand. However Purebloods are an exception, as when they die, they instead shatter into shards of glass. The most effective way to kill any vampire is to cut off their head or stab their heart using an anti-vampire weapon. Blood tablets had been developed to take the place of actual blood feeding, despite having a bad taste. Vampires also have a blood-lust that can only be quenched by the blood of their beloved.

History
Vampires have existed for well over 10,000 years, first appearing when mankind's civilizations began to crumble. At one point, they waged a war against humans, during which Purebloods began turning humans into vampires. When the number of vampires began to increase, a monarchy was established to rule the vampire race, with the Kurans as the royal family.

However, two generations ago in current times, the former king and head of the Kuran family (Rido, Haruka and Juri's father) abolished the monarchy in order to avoid authoritarianism. The Senate was established to govern the vampire realm, with high-ranking vampire aristocrats in the seats. Despite their demoted status, however, the Kuran family still holds the title as the highest standing family, and it is well known that there are many vampire families who would support Kaname Kuran if he chose to take back the kingship.

Classes
There are 5 types of vampires, ranked according to the purity of their blood. The more diluted by human blood, the lower their ranking is.

Level A (Aクラス, A Kurasu, lit. "A Class") are the Purebloods; the rarest, most elite, and most powerful class, whose blood lines have never mixed with any humans. They are the monarchy of the vampire race, meaning that they are very powerful and demonstrate many abilities such as being the only vampires able to turn humans into their own kind. However, these former human vampires are not powerful and will eventually lose their sanity and falling into Level E.

Level B (Bクラス, B Kurasu, lit. "B Class") are known as the Aristocrats. Every Aristocrat has a special ability (e.g. Hanabusa's ability to freeze vampires, humans and objects etc.) and the power to heal faster, have more strength and move more quickly. They have a small amount of human blood in their ancestry.

Level C (Cクラス, C Kurasu, lit. "C Class") are general or regular vampires.

Level D (Dクラス, D Kurasu, lit. "D Class") are humans who have been turned into a vampire by a Pureblood rather than being born as a vampire. These ex-humans would eventually go mad with blood-lust and become a "Level E" (レベルE, Rebere E) if they are not stabilized by drinking the blood of the one who originally bit them. Stabilized ex-humans are known as "Level C" or "regular vampires", and humans that have been bitten, but have not gone mad are "Level D".

Purebloods
Purebloods (純血種, Junketsushu) are level A vampires. The heritage of these vampires haven't been diluted by human blood. They are the strongest type of vampires and have the most significant powers, and can destroy any lower vampire with ease. However, despite the fact Purebloods are very powerful, they only make up only a very small portion of the vampire population. The Senate holds Purebloods in extremely high regard, to the point where it is taboo to kill or even harm a Pureblood vampire. As a result, they are treated like royalty. The powers a Pureblood vampire possesses are dangerous to both their fellow vampires and humans. Purebloods have the ability to compel lesser vampires to do their bidding. In recent chapters, Kaname Kuran demonstrated why Purebloods are feared and respected by single-handedly killing the members of the Vampire Council. If a human is bitten by a Pureblood, that human will either die of blood loss or turn into an ex-human vampire, slowly falling into a Level E. The Pureblood and ex-human in question would become bonded as Master and Servant. The master is able to completely control their servant, while the servant becomes incapable of ever killing their master, even if they wish to. When a Pureblood vampire dies, their bodies slowly disperse into small sparkles (as shown by Shizuka Hio's death in the anime) before shattering into shards of glass.

Aristocrats
Aristocrats (貴族階級, kizoku kaikyuu) are level B vampires. They are elite vampires with specialized abilities beyond normal vampires. These are also very powerful vampires, but not as powerful as Purebloods, due to having a small amount of human blood in their ancestry. They have super strength and speed, as well as specialized powers such as mind control or freezing matter. When an aristocrat is killed, they turn to dust like all other vampires, excluding Purebloods. These vampires are still able to be compelled by Purebloods, but enjoy a much more independent lifestyle in general. The Vampire Council is usually made up from their ranks.

Commons
Commons (一般階級, ippan kaikyuu, lit. "general rank") are level C vampires. These are average vampires with no significant powers. Level C vampires are not usually seen in the anime but have several different appearances throughout the manga. They only have super speed, strength and they heal faster than a normal human.

Ex-humans
Ex-humans (元人間, moto-ningen) are level D and level E vampires. They are the lowest form of vampires, humans who have been turned into vampires by being bitten by a Pureblood vampire. The E in Level E represents the word "end" because after falling to level E, it's usually the end of their life after losing control. If they don't want to die, they'll have to drink the blood of the Pureblood that bit them. The consequence is that the Pureblood would have complete control over the person and that person would truly become a vampire.

Powers
Elite vampires, such as Level B and Purebloods are known to have special powers. The following powers have been demonstrated:


 * All vampires display an accelerated healing. The purer the vampire blood, the stronger the healing factor.
 * Decelerated aging: the purer the vampire blood, the longer the life of the vampire. Purebloods are immortal. They age very slowly and they can only be killed if someone cuts off their head or if they are continuously immobilized and shot/stabbed in the heart with an anti-vampire weapon.
 * Ability to erase memories.
 * Ability to use animals as a familiar, to watch and listen.
 * Telekinetic powers, able to use these highly destructively.
 * Aristocrats most commonly display the ability to control an individual element, such as fire, ice, lightning, etc.
 * All vampires have heightened senses like their ability to smell blood from a great distance.
 * Super strength, vampires can tear through flesh with ease and destroy large concrete structures (walls, pillars, etc.) and can leap great distances
 * All vampires have accelerated speed, they are able to appear beside someone instantly.

Trivia

 * Blood to vampires can be best be compared with how water is essential to humans. Both fluids are something their respective species need to function/stay nourished. However, much like how humans can substitute other drinks for water, vampires can make due with blood tablets. While neither is sufficient in the long term for quenching thirst, said methods do keep it under control.


 * In the second series, its revealed the existence of vampires has become public knowledge. Though Pureblood are still a secret to keep the "infection" quiet.
 * Over the course of the century following Kaname's sacrifice, both pro and anti-vampire organizations popped up. Also, somehow Kaname's resting place somehow became a rumor.
 * The vampire society was governed by Yuki as queen following Kaname's death.
 * Vampires can quench their thirst for blood easily with transfusion bags and blood tablets. Its not until they fall in love that quenching their thirst becomes a problem, as their thirst can only truly be satisfied by drinking the blood of their loved one.
 * Aristocrats are noted to crave Pureblood blood by instinct. As demonstrated by Hanabusa this impulse is similar to the impulse to drink the blood of someone a vampire has feelings for, serving as an unofficial way to prove they've chosen a mate.
 * Vampire children are unable to drink blood until they have their fangs. So they take another person's energy through a kiss to be fed.
 * The most desirable blood to a vampire is ranked by a pyramid similar to the vampires level race. On top is the blood of purebloods, second is the blood of human children, third is the blood of their most beloved person.
 * A sibling can be the most beloved person to a vampire (platonically), given Ai cared for her sister after she was born. (In a sense of irony, Ren ended up craving her sister's blood.)
 * If the person a vampire cares the most about is very young, they repress their thirst around them until they get older; attempting to drink their blood when they're small is a bad idea as a vampire could accidentally drain them dry. (Ai noted she had to protect Ren from herself.)
 * When a natural born vampire gets their fangs and starts craving blood, they are isolated from the outside world for a period of time until they gain control over the impulse to feed.
 * When a female vampire becomes pregnant, it takes 2-5 years before the child is born. As a result of needing to feed for two, the mother's impulse to feed puts humans at risk (more so if the mother is a Pureblood) as it tastes better than blood tablets and vampire blood during the pregnancy.
 * The intensity of thirst seems to depend on how pure the vampire genetics are; in other words the more human one of the parents is, the baby has less vampiric instinct. Yuki noted her thirst was much more manageable when she was pregnant with Ren.
 * If a human woman becomes pregnant with a vampire's child, the pregnancy is actually no different than a regular human one; the mother suffers no odd effects.
 * When a vampire craves blood, their eyes glow red.
 * Level Es are an exception.
 * Unlike natural-born vampires, Level Es eventually lose their rationality to their thirst.
 * As a result of being dominated by their thirst, Level Es eyes are permanently crimson.