If a vampire's body is destroyed on the Material Plane and its soul is not consumed, a Vampire Wraith is born on the Spectral Plane. When a Vampire Wraith injures Raziel, it opens a wound from which it will continually draw off Raziel's energy. To halt the deadly drain, you must either slash the Vampire Wraith or flee.
These creatures grow in power the longer they dwell on the Spectral Plane. If for some reason its corpse on the Material Plane is healed, the Vampire Wraith will return to the Material Plane to reinhabit its body, bringing its deadly ability with it. These reincarnated vampires are recognizable by the sparks of blue energy they exude.
As super vampires, Vampire Wraith are deadly foes indeed.
Vampire Wraiths are souls of long-dead vampires, consigned to the Spectral Realm until they can re-enter their corpses. Their long vigil in the spirit world makes them manifest as Vampire Wraiths and they have adapted their vampire natures to the Spectral Realm, feeding on the soul energies of the other creatures that inhabit the Spectral Realm.
If a Vampire Wraith (or a Revived Vampire) lands a blow on Raziel, it's like opening a vein - they are then able to continually draw out and drain Raziel's spirit energy, even at a distance. Raziel must either close the distance and strike the Wraith to break contact, or must flee, putting a large enough distance between Raziel and the Wraith, that it can no longer maintain the connection.