Vampires

Vampires are an immortal race of humanoid beings that feed on the blood of humans. Vampires have fangs, pointed ears, and red eyes (except for Mikaela Hyakuya). The vampires, despite being former humans themselves, look down on humans and consider them mere livestock. They dislike increasing their numbers and only very rarely turn a human into a vampire. A vampire's power is dependent upon age and lineage.

Drinking human blood is insanely pleasurable to them, especially right from the source.

A vampire who starves does not die but rather becomes a demon.

Progenitors
Progenitors are shown to be the same as royalty among the vampires. All progenitors are nobles. They are quite powerful, and this power increases with greater rankings. However, progenitors of the same ranking are not necessarily equal in power. Progenitors ranked 6th and better have the right to attend meetings of the Progenitor Council. It is likely that the vampire queens and kings around the world are all high-ranking progenitors of a very high lineage.

Nobles
The Nobles are high class vampires who are far stronger than the average vampire and wield stronger weapons.

Common Vampire
Common vampires are vampires who are not nobility. They seem to be weaker than the higher classes, but remain stronger than humans.

Law

 * Vampires are forbidden from any meddling with the Curse of the Seraph.
 * In the city, vampires are forbidden from drinking blood directly from a human. They may only drink blood directly while on the surface or on the battlefield.

Aging
A newly-turned vampire can survive off of his/her sire's blood and will continue to age until drinking vampire blood, but this will only work for a limited period of time. Once the vampire drinks human blood, his/her biology stops completely, and the vampire grows tremendously in strength and power. By drinking human blood for the first time, a vampire evolves into a true vampire.

Strengths
Vampires have impressive power and regenerative abilities; this increases with their lineage and age. If they are a noble, then they have permission to turn a human into a vampire if they so choose.

In battle, they use their natural abilities as well as different types of weapons. First-class weapons pierce their hands to drink their blood in order to significantly increase their power.

They can also power-up by drinking human blood at any time.

Weaknesses

 * They have immense pride and typically underestimate their human opponents or may refuse to work together with vampires of rival factions.
 * They can be killed if their heads are destroyed. One bullet will not do the job.
 * Cursed Gear and Enchanted Gear used by the Japanese Imperial Demon Army limit their healing capabilities.
 * Their reaction to sunlight is unknown. They typically hunt at night and sleep between early morning and noon

Trivia

 * They refer to the humans as "livestock" or "humans" instead of calling them by their names.
 * Yuichiro Hyakuya reads a book in chapter 1 that erroneously tells him vampires are merely 7x as strong as humans and require arm bands to go into the sunlight.