High sorcery power, extremely long lives, high physical strength, ability to turn others into their kind
Vampires (吸血鬼 Kyūketsuki) are a conglomerate, humanoid race of beings. Most vampires are a part of the Alucard Clan.
All vampires shown are pale creatures with bright red eyes. As a general rule, they are incapable of walking directly under sunlight as it physically drains them, although the strongest of their kind are able to with little struggle.  It is not physically needed, but some vampires do indulge in drinking blood.
All shown vampires in the series are not true vampires, but rather beings who identify as them and exhibit similar abilities, making it an unusual race. Some of them have similar abilities while others do not. Both Rachel Alucard and Raquel Alucard are capable of Slave Red, for example. All vampires have incredible skill with magic, sorcery, and/or Ars Magus, and all of them are capable of regenerating wounds with little effort. However, they are not an immortal race, despite giving the impression that they are. Weapons such as the Zero-Type Izayoi and Gallia Sphyras: Outseal are capable of not only wounding vampires, but also killing them. Vampire's blood is said to have the powers of immortality. 
As well as incredible strength in the Arts, vampires also boast formidable physical prowess. In his prime, Clavis Alucard was capable of fighting both Relius Clover and Valkenhayn R. Hellsing without exhausting any effort, and the 16th Fuzzy was able to fight off Ragna the Bloodedge, Mai Natsume, Taro Sasaga'e, Shiori Kirihito, Kajun Faycott, and Bell all at the same time for an extended period using both his physical abilities and multiple Arts. 
Some vampires have demonstrated abilities unique to themselves. One such ability would be a Fuzzy's ability to create ghouls or Raquel's ability to melt into people's shadows. Despite there being no clear-cut definition or example of a vampire, it is possible for humans to transform into one if they are bit by a vampire. Humans in this state have no life-force value, and have a year until their complete transformation, lingering in a state between both life and death. When a human fully transforms into a vampire, they are said to have incredible power, and lose their sanity, attacking everyone and everything around them as their thirst for blood overcomes them. Raquel believes the only way to reverse this process is with the Azure.
Around 2050, a series of incidents happened involving Freaks. He attacked victims by biting into their necks and earned the nickname "Vampire", but it is unrelated to the species. Yuki Himezuru theorized that both vampires and werewolves were Drive-Unions.
BlazBlue: Central Fiction Library Entry
Refers to the Alucard vampire family. It applies to Rachel, and her predecessor Clavis. They live far longer than humans, but are not completely immortal. Clavis watched over the human world for over 1000 years. 
BlazBlue: Variable Heart Glossary
They have an astounding life span and tremendous sorcery power. This is the first time I've seen one, even though I am in Sector Seven. Oh, that's right, Professor Kokonoe said in the past: “That the people's thoughts can be materialized, that the fiction's and myth's concepts can be given a shape”, could he be perhaps such an existence… anyway, he is a strong existence that's for sure! - Kajun Faycott 
- BlazBlue: Bloodedge Experience - Part 1
- BlazBlue: Central Fiction, Arcade Mode, Carl Clover Victory Quote Vs Rachel Alucard, Act III
- BlazBlue: Variable Heart, Chapters 8 - 11
- BlazBlue: Central Fiction, Libary Mode, World #011
- BlazBlue: Variable Heart, Chapter 9, Glossary