Vampire Wraiths appeared in Soul Reaver; they existed in the Spectral Realm. Raziel first encountered one in Melchiah's territory.
The Vampire Wraiths were vampire souls - ones that had lingered in the Spectral Realm long enough for their predatory natures to adapt to it. They had developed shape and form, and they consumed other lost souls as Raziel and the Sluagh did. The Wraiths were more vicious than the Sluagh, always attacking Raziel even if they were alone. Once a Wraith landed a blow on him, it could devour his soul energy from a distance. To break the connection, Raziel had to strike the Wraith, or retreat a fair distance away from it. If Raziel managed to defeat a Wraith, it would make a strange screaming noise, become transparent, and he could consume it.
Like the Soul Reaver Sluagh, the Vampire Wraiths had coloured halos or auras, which indicated their level of health. A blue halo indicated that a Wraith had a lot of soul energy - green, yellow and orange indicated that it was weaker. A red halo meant that a Wraith's soul energy was almost depleted.
In Soul Reaver, the separation of a vampire's soul from its flesh was not enough to truly 'kill' it. The body remained intact in the Material Realm. Removing the cause of fatality from the vampire's body (e.g. pulling out the weapon that impaled them) would allow the soul to return, and the corpse would reanimate. If a Vampire Wraith was allowed to re-enter its body, it became a 'Revived Vampire' (as they are called in the UK Soul Reaver manual); retaining the power to drain Raziel's soul energy after a single hit.¹ Revived Vampires were easy to spot - they were mostly (if not always) adult vampires, and they could be identified by the blue sparks that surrounded them. Morlock, the Tomb Guardian, was a Revived Vampire.