A vampire is an undead being that feeds off of the lifeforce of others.
According to Kindrali, vampires have existed "for as long as strange creatures have existed in the world". The first definitively known vampire was Claret Holiday, though it is unknown how or when she became a vampire. When she left Marielda with Lilith R'ion, the two forged treaties to establish a splinter version of the Golden Lance outside the city as a line of itinerant vampire justice-dealers. Through their powers, the Lance was able to sustain itself through the Erasure.
Their undeath is of a separate sort than that of those with the curse of Nacre.
Vampires in Hieron do not need to physically drink their victims' blood of; rather, they can drain others simply by being in their presence, pulling energy inward towards themselves. When done forcefully, a mist of blood droplets may be visible in the air; some vampires may be capable of condensing this mist into a weapon such as a sword.
They may appear pale at times but healthier, stronger, and more flush when they are actively draining energy from someone.
Vampires are not mindless or inherently evil; they simply have to deal with the urge to suck in the life of others.