“Level B” Vampires, also known as Noble or Aristocrat Class Vampires, are the second most powerful class of vampire, below purebloods. Any time a pureblood has a child with a non-pureblood spouse, be they human or a lower class vampire, that child will be a Aristocrat. Aristocrats marrying other Aristocrats also produce offspring of the same power level. Their blood is not pure, but they are still incredibly powerful beings. Power level varies within this level and some versions of the pyramid nobles are grouped with common vampires, so the boundaries that separate them from Level C vampires are significantly more blurry than that which separates them from purebloods. Being considered an Aristocrat is based upon power level and relative purity of blood.
Nobles all have enhanced sight, hearing, smell, vision, speed and strength. Some appear to have the ability to tamper with memories. Additionally, they each possess at least one primary power or ability (such as the ability to manipulate fire or ice) that is somewhat unique to them. Multiple noble vampires may in fact possess the same types of powers, but to this point we haven’t seen that demonstrated.
Because of the increasing scarcity of pureblood vampires, more and more social power in the vampire world has fallen into the hands of powerful noble class vampires, especially those who over the years have made up the Vampire Council of Elders, sometimes called the vampire “Senate”.
Many nobles are well known outside of the vampire world and hold positions of power or fame as wealthy business men, politicians, famous actors, actresses and musicians and the like, although their true nature is not known to the human population who is unaware of the existence of vampires.
Nobles families appear to perpetuate and strengthen their bloodlines by offering their daughters as mistresses to eligible pureblood males in order to bring more pure blood into their families. We have not seen much of this practice, but Hanabusa Aido’s sister Tsukiko was offered to (and politely refused by) Kaname Kuran for this purpose and it may be surmised that Rido Kuran’s son Senri Shiki was probably conceived in this manner.