Sephira Crystals

Sephira Crystals (霊結晶セフイラ, Sefira Rei Kesshō) are mysterious, round, orb-like gems that contain Angels, can turn humans into Vampires, turn Vampires into "Special" Vampires and serve as the power source of their Special Vampire Form. They also have alternate forms called Qlipha Crystals that contain Demon Kings and serve as the power source of the Vampires Inverse Forms.

Bonding
In order for a Sephira Crystal to turn a human into a Vampire, or a Vampire into a "Special" Vampire, they simply need to touch it. The gem is then absorbed into the one who touched it and will turn that person into a Vampire or "Special" Vampire. When Origami was being turned into a Vampire, he described the feeling as "as if a second heart was being created inside him".

Compatibility
Human beings have varying levels of compatibility for becoming a host for the Sephira Crystals, with Phantom stating that Origami was an exceptional user due to wielding his angel so skillfully. When it comes to Vampires, however, they don't seem to wield much damage because the already had powers that they could control.

As seen from Kazuto's example, Sephira Crystals can be toxic to the host's body, and can even induce madness. As a result, Aricia stated that they need to be further refined by killing the initial host and then transplanting the gem into another host. Doing so, would ensure that the Sephira Crystals will come closer to completion and resolve the negative drawbacks. According to Aricia, while the attributes of each Sephira Crystal is pre-determined, the powers that manifest can vary depending on the personality of each host.

Removal
So far, there have shown to be three ways for a Sephira Crystal can be removed from a Vampires body. The first method is to kill the Vampire. Second, seal all the Vampires mana in Ria's body and then use a Realizer to remove it from her body in the form of a new Sephira Crystal. Finally, Artemisia has also shown the ability to remove a Qlipha Crystal through unknown means by using her territory. Ellen also says that she possesses a similar ability. Aricia has also displayed the ability to removal Sephira Crystals from their hosts by using her Angels and Astral Dress as a weapon. However, Aricia's method ultimately leads to the death of the former host.

History
According to Inverse Hideyoshi, the Sephira Crystals first emerged as Qlipha Crystals when the First Vampire decided to divided her power. The Inverse Vampire later speculates that she reversed their properties into Sephira Crystals in order to make them more compatible for human hosts.

 has had at least five Sephira Crystals in his possession, which he gave Ria Maaka, Kazuto Itsuka, Mikoto Fukawa, Origami Yasuhiro, and Mukuro Hoshimiya, turning four of them into Vampires and Ria (who was already a vampire) into a "Special" Vampire. It's currently unknown how the other Vampires acquired their Sephira Crystals.

List of Crystals

 * Sandalphon - Hideyoshi Yatogami
 * Zadkiel - Yoshino
 * Zafkiel - Ria Maaka
 * Camael - Kazuto Itsuka (currently) & Sawa Yamauchi (formerly)
 * Raphael - Kaguya Yamai & Yuzuru Yamai
 * Gabriel - Mioto Fukawa
 * Haniel - Natsuki
 * Metatron - Origami Yasuhiro
 * Rasiel - Nia Sakamaki
 * Michael - Mukuro Hoshimiya

Trivia

 * The Sephira Crystals are named after the Sephirot Tree, the tree that the Vampires are based on.
 * Since each Sephira Crystal contains an Angel inside of it, the powers of a Vampire may come from the Angels themselves and the body is simply acting as a host for manifesting the Angel's power.